============================================================================

	procedure : firs_cal 

	purpose   : calculate FIRS instrument response 

	author    : cbeck@nso Apr 2013

==============================================================================

	Check number of arguments.

==============================================================================
f n_elements(help) ne 0 then begin
print
print, "usage:   firs_cal,spat_res =spat_res ,no_av = no_av,plt =plt,ilimit = ilimit,retard = retard,theta_err = theta_err,theta_pol = theta_pol,gainindex = gainindex,darkindex = darkindex,cal_file = cal_file,change_save = change_save,input_dir = input_dir,output_dir = output_dir,flat_file = flat_file,swap = swap,add_cal = add_cal,nverbose = nverbose,cchi = cchi,n_separations = n_separations,nopause = nopause,quit_column = quit_column,help = help"
print
print, "	 Calculate FIRS polarimetric instrument response."
       print, "         "
print
print, "	Arguments"
       print, "                none"
       print
       print, "         Keywords :"
       print, "              /plt : switch on plotting (recommended)"

       print, "              spat_res: use subfields in spectra to get"
       print, "                      spatially resolved X matrices"
       print, "                      spat_res=[nx,by]; nx,ny number of subfields" 
       print, "                      in x, y dimension. For tests only."
       print, "              /no_av: do not average the measurements, use"
       print, "                      previously saved polarization vectors"
       print, "              ilimit: required intensity limit to use pixels"
       print, "                      in the calculation, fraction of imean"
       print, "              retard: retardance value to be used in degree"
       print, "              theta_err: offset angle between retarder and"
       print, "                      polarizer, in degree"
       print, "              theta_pol: position angle of polarizer during"
       print, "                      the calibration, in degree"
       print, "              add_cal: number of additional +-QU calibration"
       print, "                      files to be used in the source directory."
       print, "              /nverbose: suppress terminal output"
       print, "              cchi   : chi square value of additional +-QU"
       print, "                       vectors, measures reproduction of input"
       print, "              gainindex:number of gain table to be used for the"
       print, "                        reduction in the target directory"
       print, "              darkindex:number of dark current to be used for the"
       print, "                        reduction in the target directory"
       print, "              cal_file: number of calibration file to be used"
       print, "                        in the source directory."
       print, "              change_save: directory where the file information"
       print, "                        on the source directory was saved to."
       print, "              input_dir: source directory with raw data."
       print, "              output_dir: destination directory for reduced data."
       print, "              flat_file: use a different gain table."
       print, "                         String with the complete filepath and"
       print, "                         filename of the gain.....sav file."
       print, "               /swap   : do a swap endian of the raw data."
       print, "               n_separations: number of subdivisions along the slit."
       print, "               /nopause: ignore all stop/pause commands."
       print, "               /quit_column:switch to replace missing column at"
       print, "                         middle of IR CCD chip. Cosmetics."
       print, "               /help   : switch to active the help text above."
       print
eturn
ndif
==============================================================================

(See /home/cbeck/firs_soft2/firs_cal.pro)

============================================================================

	procedure : create_html

	purpose  : Create Overview html-page for contents of a
	           directory in the POLIS data archive.

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f n_elements(help) ne 0 then begin
print
print, "usage:  create_html,filepath = filepath,target = target,"
       print, "                    comments = comments, help = help"
print
print, "	Create Overview html-page from all ps/gif/text files"
       print, "        in a directory of the POLIS archive. Call "
       print, "        generate_archive_files before. Filename of html page"
       print, "        is generated from name of last subdirectory of"
       print, "        filepath. All gif files are linked with corresponding"
       print, "        ps-files. The text in the .txt file is included as"
       print, "        it is in the text file."
       print
print, "	Arguments"
       print, "                None."
       print
       print, "        Keywords:"
       print, "               filepath : path to input directory. Either"
       print, "                        .gif,.txt. and .ps or only .ps files"
       print, "                        must exist."
       print, "               target='text' : will be added in html page."
       print, "               comments='text' : will be added in html page."
       print, "               Warning: target and comments are only added"
       print, "               to the html file, not the text file. This is"
       print, "               not recommended, use edit_archive_txt.pro."
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/firs_create_html.pro)

============================================================================

	procedure : firs_create_mainhtml

	purpose  : Create Overview archive

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f n_elements(help) ne 0 then begin
print
print, "usage:  firs_create_mainhtml,inpath =inpath,outfile = outfile,"
       print, "                             help = help"
print
print, "	Create Overview archive page from all subdirectories"
       print, "        in a directory that contains the archive. Call "
       print, "        generate_archive_files and creat_html before. Filename is"
       print, "        hardwired in daily pages."
       print
print, "	Arguments"
       print, "                None."
       print
       print, "        Keywords:"
       print, "               inpath : path to input directory of the archive"
       print, "               outfile: string(1), name of final html file, should"
       print, "                        be changed."
       print, "               /help  : display this help text" 
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/firs_create_mainhtml.pro)

============================================================================

	procedure :  firs_view

	purpose   :  display spectra of raw and merged data files

       written   :  cbeck@KIS 06/02
==============================================================================

	Check number of parameters.

======================================
f n_params() lt 1 then begin
print
print, "usage:  firs_view, infile,swap = swap"
print
       print, "        Display spectra of reduced FIRS data files."
       print, "        Plot row or column profiles, save single images as"
       print, "        ps-files. Raw data are squeezed to fit on the display" 
       print, "        pixel positions of features have to be derived from"
       print, "        the values printed above the column or row plots."
print
print, "	Arguments"
print, "		infile	              : input data file"
       print
print, "	Keywords"
       print, "               swap : if running IDL on a Sun you have"
       print, "                          to set /swap"
       print 
return
ndif
============================================================================

(See /home/cbeck/firs_soft2/firs_view.pro)

============================================================================

	function : float2int

	purpose  : transform data array in floating format into integer array.

       calls    : round.pro, fix.pro (idl-implemented)

	written :  cbeck@KIS 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  i = float2int(array,unsigned)
print
print, "	Transform floating array into integer array,"
       print, "        either signed or unsigned."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		array : floating array
       print
       print, "                Output:"
       print, "                (un)signed integer array, rounded"
       print
       print, "        Keywords:"
       print, "                /unsigned : transform to unsigned integer"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/float2int.pro)

 NAME: 
	FXHREAD
 Purpose     : 
       Reads a FITS header from an opened disk file.
 Explanation : 
       Reads a FITS header from an opened disk file.
 Use         : 
	FXHREAD, UNIT, HEADER  [, STATUS ]
 Inputs      : 
	UNIT	= Logical unit number.
 Opt. Inputs : 

 Outputs     : 
	HEADER	= String array containing the FITS header.
 Opt. Outputs: 
	STATUS	= Condition code giving the status of the read.  Normally, this
		  is zero, but is set to !ERR if an error occurs, or if the
		  first byte of the header is zero (ASCII null).
 Keywords    : 
	None.
 Calls       : 
	None.
 Common      : 
	None.
 Restrictions: 
	The file must already be positioned at the start of the header.  It
	must be a proper FITS file.
 Side effects: 
	The file ends by being positioned at the end of the FITS header, unless
	an error occurs.
 Category    : 
	Data Handling, I/O, FITS, Generic.
 Prev. Hist. : 
	W. Thompson, Feb 1992, from READFITS by J. Woffard and W. Landsman.
	W. Thompson, Aug 1992, added test for SIMPLE keyword.
 Written     : 
	William Thompson, GSFC, February 1992.
 Modified    : 
	Version 1, William Thompson, GSFC, 12 April 1993.
		Incorporated into CDS library.
 Version     : 
	Version 1, 12 April 1993.
	Converted to IDL V5.0   W. Landsman   September 1997

(See /home/cbeck/firs_soft2/fxhread.pro)

 NAME: 
        FXPAR()
 PURPOSE: 
       Obtain the value of a parameter in a FITS header.
 EXPLANATION: 
       The first 8 chacters of each element of HDR are searched for a match to
       NAME.  If the keyword is one of those allowed to take multiple values
       ("HISTORY", "COMMENT", or "        " (blank)), then the value is taken
       as the next 72 characters.  Otherwise, it is assumed that the next
       character is "=", and the value (and optional comment) is then parsed
       from the last 71 characters.  An error occurs if there is no parameter
       with the given name.
      
       If the value is too long for one line, it may be continued on to the
       the next input card, using the CONTINUE Long String Keyword convention.
       For more info, http://fits.gsfc.nasa.gov/registry/continue_keyword.html
       

       Complex numbers are recognized as two numbers separated by one or more
       space characters.

       If a numeric value has no decimal point (or E or D) it is returned as
       type LONG.  If it contains more than 8 numerals, or contains the
       character 'D', then it is returned as type DOUBLE.  Otherwise it is
       returned as type FLOAT.    If an integer is too large to be stored as
       type LONG, then it is returned as DOUBLE.

 CALLING SEQUENCE: 
       Result = FXPAR( HDR, NAME  [, ABORT, COUNT=, COMMENT=, /NOCONTINUE ] )

       Result = FXPAR(HEADER,'DATE')           ;Finds the value of DATE
       Result = FXPAR(HEADER,'NAXIS*')         ;Returns array dimensions as
                                               ;vector
 REQUIRED INPUTS: 
       HDR     = FITS header string array (e.g. as returned by FXREAD).  Each
                 element should have a length of 80 characters
       NAME    = String name of the parameter to return.  If NAME is of the
                 form 'keyword*' then an array is returned containing values
                 of keywordN where N is an integer.  The value of keywordN
                 will be placed in RESULT(N-1).  The data type of RESULT will
                 be the type of the first valid match of keywordN
                 found, unless DATATYPE is given.
 OPTIONAL INPUT: 
       ABORT   = String specifying that FXPAR should do a RETALL if a
                 parameter is not found.  ABORT should contain a string to be
                 printed if the keyword parameter is not found.  If not
                 supplied, FXPAR will return with a negative !err if a keyword
                 is not found.
       DATATYPE = A scalar value, indicating the type of vector
                  data.  All keywords will be cast to this type.
                  Default: based on first keyword.
                  Example: DATATYPE=0.0D (cast data to double precision)
       START   = A best-guess starting position of the sought-after
                 keyword in the header.  If specified, then FXPAR
                 first searches for scalar keywords in the header in
                 the index range bounded by START-PRECHECK and
                 START+POSTCHECK.  This can speed up keyword searches
                 in large headers.  If the keyword is not found, then
                 FXPAR searches the entire header.  

                 If not specified then the entire header is searched.
                 Searches of the form 'keyword*' also search the
                 entire header and ignore START.

                 Upon return START is changed to be the position of
                 the newly found keyword.  Thus the best way to
                 search for a series of keywords is to search for
                 them in the order they appear in the header like
                 this:

                       START = 0L
                       P1 = FXPAR('P1', START=START)
                       P2 = FXPAR('P2', START=START)
       PRECHECK = If START is specified, then PRECHECK is the number
                  of keywords preceding START to be searched.
                  Default: 5
       POSTCHECK = If START is specified, then POSTCHECK is the number
                   of keywords after START to be searched.
                   Default: 20
 OUTPUT: 
       The returned value of the function is the value(s) associated with the
       requested keyword in the header array.

       If the parameter is complex, double precision, floating point, long or
       string, then the result is of that type.  Apostrophes are stripped from
       strings.  If the parameter is logical, 1 is returned for T, and 0 is
       returned for F.

       If NAME was of form 'keyword*' then a vector of values are returned.

 OPTIONAL INPUT KEYWORDS: 
       /NOCONTINUE = If set, then continuation lines will not be read, even
                 if present in the header
 OPTIONAL OUTPUT KEYWORD:
       COUNT   = Optional keyword to return a value equal to the number of
                 parameters found by FXPAR.
       COMMENTS= Array of comments associated with the returned values.

 PROCEDURE CALLS: 
       GETTOK(), VALID_NUM
 SIDE EFFECTS: 

       The system variable !err is set to -1 if parameter not found, 0 for a
       scalar value returned.  If a vector is returned it is set to the number
       of keyword matches found.

       If a keyword occurs more than once in a header, a warning is given,
       and the first occurence is used.  However, if the keyword is "HISTORY",
       "COMMENT", or "        " (blank), then multiple values are returned.

 NOTES:
	The functions SXPAR() and FXPAR() are nearly identical, although
	FXPAR() has slightly more sophisticated parsing.   There is no
	particular reason for having two nearly identical procedures, but
	both are too widely used to drop either one.

 REVISION HISTORY: 
       Version 1, William Thompson, GSFC, 12 April 1993.
               Adapted from SXPAR
       Version 2, William Thompson, GSFC, 14 October 1994
               Modified to use VALID_NUM instead of STRNUMBER.  Inserted
               additional call to VALID_NUM to trap cases where character
               strings did not contain quotation marks.
       Version 3, William Thompson, GSFC, 22 December 1994
               Fixed bug with blank keywords, following suggestion by Wayne
               Landsman.
       Version 4, Mons Morrison, LMSAL, 9-Jan-98
               Made non-trailing ' for string tag just be a warning (not
               a fatal error).  It was needed because "sxaddpar" had an
               error which did not write tags properly for long strings
               (over 68 characters)
       Version 5, Wayne Landsman GSFC, 29 May 1998
               Fixed potential problem with overflow of LONG values
       Version 6, Craig Markwardt, GSFC, 28 Jan 1998, 
               Added CONTINUE parsing         
       Version 7, Craig Markwardt, GSFC, 18 Nov 1999,
               Added START, PRE/POSTCHECK keywords for better
               performance
       Version 8, Craig Markwardt, GSFC, 08 Oct 2003,
               Added DATATYPE keyword to cast vector keywords type
       Version 9, Paul Hick, 22 Oct 2003, Corrected bug (NHEADER-1)

(See /home/cbeck/firs_soft2/fxpar.pro)

 NAME: 
	FXREAD
 Purpose     : 
	Read basic FITS files.
 Explanation : 
	Read an image array from a disk FITS file.  Optionally allows the
	user to read in only a subarray and/or every Nth pixel.
 Use         : 
	FXREAD, FILENAME, DATA  [, HEADER  [, I1, I2  [, J1, J2 ]]  [, STEP]]
 Inputs      : 
	FILENAME = String containing the name of the file to be read.
 Opt. Inputs : 
	I1,I2	 = Data range to read in the first dimension.  If passed, then
		   HEADER must also be passed.  If not passed, or set to -1,-1,
		   then the entire range is read.
	J1,J2	 = Data range to read in the second dimension.  If passed, then
		   HEADER and I1,J2 must also be passed.  If not passed, or set
		   to -1,-1, then the entire range is read.
	STEP	 = Step size to use in reading the data.  If passed, then
		   HEADER must also be passed.  Default value is 1.  Ignored if
		   less than 1.
 Outputs     : 
	DATA	 = Data array to be read from the file.
 Opt. Outputs: 
	HEADER	 = String array containing the header for the FITS file.
 Keywords    : 
       /COMPRESS - If this keyword is set and non-zero, then then treat
                the file as gzip compressed.    By default FXREAD assumes
                the file is gzip compressed if it ends in ".gz"
	NANVALUE = Value signalling data dropout.  All points corresponding to
		   IEEE NaN (not-a-number) are set to this value.  Ignored
		   unless DATA is of type float or double-precision.
       EXTENSION = FITS extension.  It can be a scalar integer,
                indicating the extension number (extension number 0
                is the primary HDU).  It can also be a scalar string,
                indicating the extension name (EXTNAME keyword).
                Default: 0 (primary HDU)
	PROMPT	 = If set, then the optional parameters are prompted for at the
		   keyboard.
	AVERAGE	 = If set, then the array size is reduced by averaging pixels
		   together rather than by subselecting pixels.  Ignored unless
		   STEP is nontrivial.  Note:  this is much slower.
	YSTEP	 = If passed, then STEP is the step size in the 1st dimension,
		   and YSTEP is the step size in the 2nd dimension.  Otherwise,
		   STEP applies to both directions.
	NOSCALE	 = If set, then the output data will not be scaled using the
		   optional BSCALE and BZERO keywords in the FITS header.
		   Default is to scale, if and only if BSCALE and BZERO are
		   present and nontrivial.
	NOUPDATE = If set, then the optional BSCALE and BZERO keywords in the
		   optional HEADER array will not be changed.  The default is
		   to reset these keywords to BSCALE=1, BZERO=0.  Ignored if
		   NOSCALE is set.
	ERRMSG   = If defined and passed, then any error messages will be
		   returned to the user in this parameter rather than
		   depending on the MESSAGE routine in IDL.  If no errors are
		   encountered, then a null string is returned.  In order to
		   use this feature, ERRMSG must be defined first, e.g.

			ERRMSG = ''
			FXREAD, ERRMSG=ERRMSG, ...
			IF ERRMSG NE '' THEN ...
       NODATA   = If set, then the array is not read in, but the
                  primary header is read.

 Calls       : 
	GET_DATE, IEEE_TO_HOST, FXADDPAR, FXHREAD, FXPAR, WHERENAN
 Common      : 
	None.
 Restrictions: 
	Groups are not supported.

	The optional parameters I1, I2, and STEP only work with one or
	two-dimensional arrays.  J1 and J2 only work with two-dimensional
	arrays.

	Use of the AVERAGE keyword is not compatible with arrays with missing
	pixels.

 Side effects: 
	If the keywords BSCALE and BZERO are present in the FITS header, and
	have non-trivial values, then the returned array DATA is formed by the
	equation

			DATA = BSCALE*original + BZERO

	However, this behavior can overridden by using the /NOSCALE keyword.

	If the data is scaled, then the optional HEADER array is changed so
	that BSCALE=1 and BZERO=0.  This is so that these scaling parameters
	are not applied to the data a second time by another routine.  Also,
	history records are added storing the original values of these
	constants.  Note that only the returned array is modified--the header
	in the FITS file itself is untouched.

	If the /NOUPDATE keyword is set, however, then the BSCALE and BZERO
	keywords are not changed.  It is then the user's responsibility to
	ensure that these parameters are not reapplied to the data.  In
	particular, these keywords should not be present in any header when
	writing another FITS file, unless the user wants their values to be
	applied when the file is read back in.  Otherwise, FITS readers will
	read in the wrong values for the data array.
	
 Category    : 
	Data Handling, I/O, FITS, Generic.
 Prev. Hist. : 
	W. Thompson, May 1992, based in part on READFITS by W. Landsman, and
			       STSUB by M. Greason and K. Venkatakrishna.
	W. Thompson, Jun 1992, added code to interpret BSCALE and BZERO
			       records, and added NOSCALE and NOUPDATE
			       keywords.
	W. Thompson, Aug 1992, changed to call FXHREAD, and to add history
			       records for BZERO, BSCALE.
 Minimium IDL Version:
       V5.3 (uses COMPRESS keyword to OPEN) 
 Written     : 
	William Thompson, GSFC, May 1992.
 Modified    : 
	Version 1, William Thompson, GSFC, 12 April 1993.
		Incorporated into CDS library.
	Version 2, William Thompson, GSFC, 17 November 1993.
		Corrected bug with AVERAGE keyword on non-IEEE compatible
		machines.
		Corrected bug with subsampling on VAX machines.
	Version 3, William Thompson, GSFC, 31 May 1994
		Added ERRMSG keyword.
       Version 4, William Thompson, GSFC, 23 June 1994
               Modified so that ERRMSG is not touched if not defined.
       Version 5, Zarro (SAC/GSFC), 14 Feb 1997 
               Added I/O error checking
       Version 6, 20-May-1998, David Schlegel/W. Thompson
               Allow a single pixel to be read in.
               Change the signal to read in the entire array to be -1
       Version 7 C. Markwardt 22 Sep 2003
               If the image is empty (NAXIS EQ 0), or NODATA is set, then
               return only the header.  
       Version 8 W. Landsman  29 June 2004
               Added COMPRESS keyword, check for .gz extension  
       Version 9, William Thompson, 19-Aug-2004
               Make sure COMPRESS is treated as a scalar
       Version 10, Craig Markwardt, 01 Mar 2004
               Add EXTENSION keyword and ability to read different
               extensions than the primary one.
       Version 11,  W. Landsamn   September 2006 
               Assume since V5.5, remove VMS support
       Version 11.1,  W. Landsamn   November 2007
               Allow for possibility number of bytes requires 64 bit integer
       Version 12, William Thompson, 18-Jun-2010, update BLANK value.

(See /home/cbeck/firs_soft2/fxread.pro)

 NAME:
	GETTOK                                    
 PURPOSE:
	Retrieve the first part of a (vector) string up to a specified character
 EXPLANATION:
	GET TOKen - Retrieve first part of string until the character char 
	is encountered.   

 CALLING SEQUENCE:
	token = gettok( st, char, [ /EXACT ] )

 INPUT:
	char - character separating tokens, scalar string

 INPUT-OUTPUT:
	st - string to get token from (on output token is removed),
            scalar or vector

 OUTPUT:
	token - extracted string value is returned, same dimensions as st
 OPTIONAL INPUT KEYWORD:
       /EXACT -  The default behaviour of GETTOK is to remove any leading 
              blanks and (if the token is a blank) convert tabs to blanks.    
              Set the /EXACT keyword to skip these steps and leave the 
              input string unchanged before searching for the  character 
              tokens. 

 EXAMPLE:
	If ST is ['abc=999','x=3.4234'] then gettok(ST,'=') would return
	['abc','x'] and ST would be left as ['999','3.4234'] 

 PROCEDURE CALLS:
       REPCHR()
 HISTORY
	version 1  by D. Lindler APR,86
	Remove leading blanks    W. Landsman (from JKF)    Aug. 1991
	Converted to IDL V5.0   W. Landsman   September 1997
       V5.3 version, accept vector input   W. Landsman February 2000
       Slightly faster implementation  W. Landsman   February 2001
       Added EXACT keyword  W. Landsman March 2004
       Assume since V5.4, Use COMPLEMENT keyword to WHERE W. Landsman Apr 2006

(See /home/cbeck/firs_soft2/gettok.pro)

==============================================================================

	function: get_angles

	purpose : return the incidence and rotation angles for the
	          choosen azimuth of first mirror and date, Cap. equations

       written : manolo collados@iac
       edited  : cbeck@KIS, 12/01

==============================================================================

       Check number of parameters.

==============================================================================
f n_params() lt 5 then begin
print
print, "usage:	angles = get_angles(azi,yy,mm,dd,hh)"
print
       print, "        Calculate all needed angles from coelostat settings."
       print, "        Return i1,th1,i2,th2,i3,th3,i4 in degrees."
print
print, "	Arguments"
       print, "                azi : azimuth of first mirror, positive values"
       print, "                      towards east"
       print, "                yy,mm,dd,hh : date and time in the form"
       print, "                      01,06,12,12.345 UT"
       print
       print, "                Output angles are in degrees."
       print, "        Output"
       print, "                vector(7),[i1,th1,i2,th2,i3,th3,i4]"
       print, "                i1,i2,i3=i4 : incidence angles on C1, C2, main"
print, "                th1         : rotation between sun and C1"
       print, "                th2         : rotation between C1 nad C2"
       print, "                th3         : rotation between C2 and main"
       print
return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/get_angles.pro)

==============================================================================

	function: get_angles_final

	purpose : return the incidence and rotation angles for the
	          choosen azimuth of first mirror and date
                 Additionally polarizer rotation for tel.cal.data

       written : cbeck@KIS, 11/01

==============================================================================

       Check number of parameters.

==============================================================================
f n_params() lt 5 then begin
print
print, "usage:	angles = get_angles_final(azi,yy,mm,dd,hh)"
print
       print, "        Calculate all needed angles from coelostat settings."
       print, "        Return i1,th1,i2,th2,i3,th3,i4 as in get_angles.pro."
       print, "        Also returned : th_pol_C1,th_C1_pol,th_pol_C2."
       print, "        Needed only for polarizer on C1."
       print, "        Calculation is partly analytically/numerically."
print
print, "	Arguments"
       print, "                azi : azimuth of first mirror, positive values"
       print, "                      towards east"
       print, "                yy,mm,dd,hh : date and time in the form"
       print, "                      01,06,12,12.345 UT"
print
       print, "        Keywords"
       print, "                /earth : RF0 fixed on earth"
       print
       print, "                Output angles are in degrees."
       print, "        Output"
       print, "                vector(10),[i1,th1,i2,th2,i3,th3,i4,$"
       print, "                th_pol_C1,th_C1_pol,th_pol_C2]"
       print, "                i1,i2,i3  : incidence angles on C1, C2, main"
print, "                th1       : rotation between RF0 and C1"
       print, "                th2       : rotation between C1 nad C2"
       print, "                th3       : rotation between C2 and main"
print, "                th_pol_C1 : rotation between polarizer and C1"
print, "                th_C1_pol : rotation between reflected beam of"
       print, "                            C1 and polarizer"
print, "                th_pol_C2 : rotation between polarizer and C2"
       print
return, 0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/get_angles_final.pro)

 NAME:
       GET_DATE
 PURPOSE:
       Return the (current) UTC date in CCYY-MM-DD format for FITS headers
 EXPLANATION:
       This is the format required by the DATE and DATE-OBS keywords in a 
       FITS header.  

 CALLING SEQUENCE:
       GET_DATE, FITS_date, [ in_date, /OLD, /TIMETAG ]
 OPTIONAL INPUTS:
       in_date - string (scalar or vector) containing dates in IDL
            systime() format (e.g. 'Tue Sep 25 14:56:14 2001')
 OUTPUTS:
       FITS_date = A scalar character string giving the current date.    Actual
               appearance of dte depends on which keywords are supplied.
       
       No Keywords supplied - dte is a 10 character string with the format
               CCYY-MM-DD where  represents a calendar year,  the
               ordinal number of a calendar month within the calendar year, 
               and 
 the ordinal number of a day within the calendar month.
       /TIMETAG set - dte is a 19 character string with the format
               CCYY-MM-DDThh:mm:ss where  represents the hour in the day,
                 the minutes,  the seconds, and the literal 'T' the 
               ISO 8601 time designator
       /OLD set - dte is an 8 character string in DD/MM/YY format

 INPUT KEYWORDS:
       /TIMETAG - Specify the time to the nearest second in the DATE format
       /OLD - Return the DATE format formerly (pre-1997) recommended for FITS
               Note that this format is now deprecated because it uses only
               a 2 digit representation of the year. 
 EXAMPLE:
       Add the current date to the DATE keyword in a FITS header,h
     
       IDL> GET_DATE,dte
       IDL> sxaddpar, h, 'DATE', dte, 'Date header was created'

 NOTES:
       (1) A discussion of the DATExxx syntax in FITS headers can be found in
       http://www.cv.nrao.edu/fits/documents/standards/year2000.txt

       (2) Those who wish to use need further flexibility in their date 
       formats (e.g. to use TAI time) should look at Bill Thompson's time
       routines in http://sohowww.nascom.nasa.gov/solarsoft/gen/idl/time

 PROCEDURES USED:
       DAYCNV - Convert Julian date to Gregorian calendar date
 REVISION HISTORY:
       Written      W. Landsman          March 1991
       Major rewrite to write new DATExxx syntax  W. Landsman  August 1997
       Converted to IDL V5.0   W. Landsman   September 1997
       Work after year 2000 even with /OLD keyword W. Landsman January 2000
       Don't need to worry about TIME_DIFF since V5.4 W. Landsman July 2001
       Assume since V5.4, remove LOCAL_DIFF keyword  W. Landsman April 2006

(See /home/cbeck/firs_soft2/get_date.pro)

============================================================================

	procedure : get_firs_dataprop

	purpose   : get settings of observations on one day

	author    : cbeck@nso Apr 2013

==============================================================================

f n_elements(help) ne 0 then begin
print
print, "usage:   get_firs_dataprop, input_dir,change_save = change_save,help= help"
print
print, "	 Get settings of all FIRS observations in one directory."
       print, "         "
print
print, "	Arguments"
       print, "                input_dir"
       print
       print, "         Keywords :"
       print, "              change_save: directory where the file information"
       print, "                        on the source directory will be saved to."
       print, "                          To be used if you do not have write"
       print, "                          permission in source directory."
       print, "               /help   : switch to active the help text above."
       print
eturn
ndif
==============================================================================

(See /home/cbeck/firs_soft2/get_firs_dataprop.pro)

==============================================================================

	function: get_mirrors

	purpose : return the reflectivities and retardance of all mirrors

       calls   : calculate_mirrors.pro

       edited  : cbeck@KIS, 12/01

==============================================================================

       Check number of parameters.

==============================================================================
f n_params() lt 9 then begin
print
print, "usage:	mir =  get_mirrors(n_coel,k_coel,n_vac,k_vac,d_lambda"
       print, "               ,nu,i1,i2,i3)"
print
       print, "        Calculate mirror reflectivities from refractive"
       print, "        indices and incidence angles."
print
print, "	Arguments"
       print, "                n_coel   : refraction index coelostat"
       print, "                k_coel   : absorption coefficient coel."
       print, "                n_vac    : refraction index main/defl."
       print, "                k_vac    : absoption coefficient main/defl."
       print, "                d_lambda : thickness of coating in wave-length"
       print, "                           fractions d/lambda"
       print, "                nu       : refraction index of substrat"
       print, "                i1,i2,i3 : incidence angle on C1, C2, main"
       print
       print, "        Output"
       print, "                vector(9),[coel1rp,coel1rs,coel1ret,coel2rp$"
       print, "                       ,coel2rs,coel2ret,prirp,prirs,priret]"
       print
       print, "                coel1rs : reflectivity perpendicular to plain"
       print, "                          of incidence, C1"
       print, "                coel1rp : reflectivity in the plain of"
       print, "                          incidence, C1"
       print, "                coel1ret: retardance of first mirror C1"
       print, "                coel2rs : reflectivity perpendicular to plain"
       print, "                          of incidence, C2"
       print, "                coel2rp : reflectivity in the plain of"
       print, "                          incidence, C2"
       print, "                coel2ret: retardance of second mirror C2"
       print, "                prirs   : reflectivity perpendicular to plain"
       print, "                          of incidence, main and deflection"
       print, "                prirp   : reflectivity in the plain of"
       print, "                          incidence, main and deflection"
       print, "                priret  : retardance of main and deflection"
       print, "                          mirror"
       print
       print, "        Keywords:"
       print, "                opticthick : calculation as in Cap. 1989"
       print, "                             d_lambda and nu are ignored"
       print
       print, "        Calculation as in the appendix of Skumanich et al.,"
       print, "        1997"
return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/get_mirrors.pro)

============================================================================

	function : get_tmatrix

	purpose  : return normalized telescope matrix

	written :  cbeck@kis 12/01

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 6) then begin
print
print, "usage:  T = get_tmatrix(date,mirrorparam,fitparam,azimuth,"
       print, "                    xswitch1,xi,(alpha,beta),/ideal, /earth,"
       print, "                    /polarizer, /unnormalized)"
print
print, "	Use date and azimuth to construct geometry of VTT"
       print, "        coelostat and beam path. Calculate rotation and"
       print, "        incidence angles. Calculate mirror properties from"
       print, "        refraction indices. Use the fit values for the exit"
       print, "        and entry windows."
       print
print, "	Arguments"
print, "		date :  vector(4),[year,month,day,hour] in UT"
       print, "                mirrorparam : vector(4), [n,k,d_lambda,nu]"
       print, "                fitparam    : vector(5), [offout,winang,$"
       print, "                                      winret,exang,exret]"
       print, "                azimuth  : position of C1, positive to E"
       print, "                xswitch1 : Capitani (0) or Beck (1) angles."
       print, "                           If the \polarizer or \earth is to"
       print,"                            be used, xswitch1 must be set to 1"
       print, "                xi       : position angle of linear polarizer"
       print, "                           On C1: Positive from N to E"
       print, "                           On window: Positive from W to N"
       print, "                alpha,beta : properties of tel.cal.polarizer"
       print, "                             see vtt_ten.pro for meaning"
       print
       print, "        Keywords"
       print, "                /ideal     : use ideal mirrors"
       print, "                /earth     : fix RF0 on earth"
       print, "                polarizer =1 : put linear polarizer on C1"
       print, "                polarizer =2 : put polarizer on window"
       print, "                /opticthick : use thick coatings"
       print, "                /unnormalized : no intensity normalization"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/get_tmatrix.pro)

============================================================================

	function : histogra

	purpose  : calculate histogram of vector into n equidistant bins

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 2) then begin
print
print, "usage:  erg = histogra(x,bins)"
print
print, "	Calculate histogram of values in x into #bins, which"
       print, "        are equidistant between max and min of x."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		x : vector of values"
       print, "                bins : number of bins to use"
       print
       print, "                Output :"
       print, "                erg(0:bins-1) = histogram values in bins"
       print, "                erg(bins:bins*2-1) = central position of bins"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/histogra.pro)

============================================================================

	function : histogra2d

	purpose  : calculate histogram of vector x into n equidistant bins.
                  Additionally averages values of dependent variable
                  y1 in the bins.

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 3) then begin
print
print, "usage:  erg = histogra(x,y1,bins)"
print
print, "	Calculate histogram of values in x into #bins, which"
       print, "        are equidistant between max and min of x."
       print, "        Additionally calculate the average value of the"
       print, "        dependent variable y1 = f(x) in the bins."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		x : vector of values"
       print, "                bins : number of bins to use"
       print
       print, "                Output :"
       print, "                erg(0:bins-1) = histogram values in bins"
       print, "                erg(bins:bins*2-1) = central position of bins"
       print, "                erg(bins*2:bins*3-1) = average values of y1"
       print, "                erg(bins*3:bins*4-1) = rms of y1"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/histogra2d.pro)

 NAME: ibis_tmxt.pro
       

 PURPOSE: Calculate T-matrix for Dunn Solar Telescope

 CATEGORY:

 CALLING SEQUENCE:
       
 ibis_tmtx, tparams, lambda, tp_azim, tp_elev, tp_table

 INPUTS: tparams, lambda, tp_azim, tp_elev, tp_table

 KEYWORD PARAMETERS: none

 OUTPUTS: 4x4 Mueller matrix of telescope
       

 OPTIONAL OUTPUTS:

 EXAMPLE:

 MODIFICATION HISTORY:

(See /home/cbeck/firs_soft2/ibis_tmtx.pro)

 NAME:
     IEEE_TO_HOST
 PURPOSE:
     Translate an IDL variable from IEEE-754 to host representation 
 EXPLANATION:
     The variable is translated from IEEE-754 ("big-endian" as used, for
     example, in FITS data ), into the host machine architecture.

     Duplicates most of the functionality of the SWAP_ENDIAN_INPLACE procedure
     introduced in V5.6, with the addition of the IDLTYPE keyword.
 CALLING SEQUENCE:
     IEEE_TO_HOST, data, [ IDLTYPE = , ]

 INPUT-OUTPUT PARAMETERS:
     data - any IDL variable, scalar or vector.   It will be modified by
             IEEE_TO_HOST to convert from IEEE to host representation.  Byte 
             and string variables are returned by IEEE_TO_HOST unchanged

 OPTIONAL KEYWORD INPUTS:
     IDLTYPE - scalar integer (1-15) specifying the IDL datatype according
               to the code given by the SIZE function.     This keyword
               is usually when DATA is a byte array to be interpreted as
               another datatype (e.g. FLOAT).

 EXAMPLE:
       A 2880 byte array (named FITARR) from a FITS record is to be 
       interpreted as floating and converted to the host representaton:

       IDL> IEEE_TO_HOST, fitarr, IDLTYPE = 4     

 METHOD:
       The BYTEORDER procedure is called with the appropriate keyword

 MODIFICATION HISTORY:
      Written, W. Landsman   Hughes/STX   May, 1992
      Converted to IDL V5.0   W. Landsman   September 1997
      Under VMS check for IEEE -0.0 values   January 1998
      VMS now handle -0.0 values under IDL V5.1    July 1998
      Added new integer datatypes  C. Markwardt/W. Landsman  July 2000
      Post-V5.1 version, no VMS negative zero check  W. Landsman July 2001
      Use size(/type)  W. Landsman December 2002
      Use /SWAP_IF_LITTLE_ENDIAN keyword for 64bit types W. Landsman Feb 2003
      Do not use XDR keywords to BYTEORDER for much improved speed
                               W. Landsman   April 2006
      Update cosmetic typo for structures W. Landsman  October 2006

(See /home/cbeck/firs_soft2/ieee_to_host.pro)

============================================================================

	function : integrator

	purpose  : calculate integral of curve by linear interpolation

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  erg = integrator(x)"
print
print, "	Calculate integral of 1-D vector by linear interpolation."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		x : curve values"
       print
       print, "                Output :"
       print, "                erg = integral of x"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/integrator.pro)

============================================================================

	function : invert_svd

	purpose  : invert n x m matrix using singular value decomposition 

       uses     : svdc IDL-implemented

	written  :  MCV ?

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  erg = invert_svd(mat,tol = tol)"
print
print, "	Invert matrix mat using singular value decomposition."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		mat : n x m matrix"
       print
       print, "        Keywords:"
       print, "                tol : limit for disregarding Eigenvalues"
       print
       print, "                Output :"
       print, "                erg = inverse of matrix mat"
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/invert_svd.pro)

==============================================================================

	procedure : iterate_gain

	purpose   : find optimal shift vale by least-square-fit to minimize
	            deviation of gaintable line from straight line

       calls     : analytger.pro

       written   : cbeck@KIS 3/03 

==============================================================================

	Check number of parameters.

==============================================================================
f n_params() lt 6 then begin
print
print, "usage:  iterate_gain,shift_val,i_line,mean_line,gain_line,"
       print, "                     xswitch,wave_lim,plt = plt,"
       print, "                     err_index = err_index"
       print
print, "	Find the optimal shift value for mean profile by"
       print, "        minimizing deviation of gaintable line from a"
       print, "        straight line."
     	print
print, "	Arguments"
  	print, "        Input:"
print, "	     i_line     : line of flat field image"
       print, "             mean_line  : mean profile"
       print, "             gain_line  : rough gainline by division"
       print, "             xswitch    : switch to modify speed"
       print, "             wave_lim   : wave_lim = [low,high] fixes spectral"
       print, "                          range for least-square fit to shift."
       print, "                          wave_lim = [low,high,speed], speed"
       print, "                          controls convergence of fit,"
       print, "                       0.5 < speed < 4."
       print, "        Output:"
       print, "               shift_val : iterated shift value"
print
print, "	Keywords"
       print, "	       verbose	 : give run-time info"
print
return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/iterate_gain.pro)

============================================================================

	procedure : legend1 

	purpose   : add legend to a plot.

	written   :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f n_elements(help) ne 0 then begin
print
print, "usage:  legend1,text =text,psym = psym,linestyle = linestyle,"
       print, "                pos = pos,charsize=charsize,color = color,"
       print, "                data = data,normal = normal,ppsym2 = ppsym2,"
       print, "                llinestyle2 = llinestyle2,ccolor2 = ccolor2,"
       print, "                ccharsize2 = ccharsize2,no_box = no_box,"
       print, "                thick = thick,charthick = charthick,"
       print, "                ttextcolor = ttextcolor,long = long,"
       print, "                help = help"
print
print, "	Overplot legend to a graph. legend1 can do"
       print, "        symbols and lines with variable colors."
       print, "        2 symbols and/or lines may be combined in one row."
       print
print, "	Keywords:"
       print, "                text : text for each row, may be empty string"
       print, "                psym,ppsym2 : symbol type of symbol 1/2"
       print, "                linestyle, llinestyle2 : same for lines"
       print, "                data,normal: as usual"
       print, "                pos : position of legend, either"
       print, "                      pos = 0 left upper corner"
       print, "                      pos = 1 right upper corner"
       print, "                      pos = 2 right lower corner"
       print, "                      pos = 3 left lower corner"
       print, "                or pos = [x0,y0] lower left corner of text"
       print, "                no_box : omit borderline around text"
       print, "                charsize : size of text characters"
       print, "                ccharsize2 : size of symbols"
       print, "                color, ccolor2 : color of first or second"
       print, "                                 symbol or line"
       print, "                ttextcolor : color of text"
       print, "                /long : extend lines if necessary (e.g. dashed)"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/legend1.pro)

============================================================================

	function : length

	purpose  : return length of vector

       calls    : size.pro (idl-implemented)

	written :  cbeck@KIS 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  N = length(x)"
print
       print, "        Return length of 1-dimensional vector."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		x : vector"
       print
       print, "                Output:"
       print, "                N = number of entries"
eturn,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/length.pro)

 Procedure:         LPFF

 Purpose:           Measures the position of a spectral line (absorption
                    or emission within the interval specified.

 Category:          Spectral Analysis

 Calling sequence:  LPFF,interval,pos[,wl=wl,pix=pix,vel=vel,plot=plot]  

 Input:             arr: 1-dim array containing the line profile

 optional Input:    wl:  Wavelength in nm
                    pix: pixel size in pm

 optional keyword:  plot: ...

 Output:            pos: position of line at subpixel accuracy,
                         measured from left boundary of 'arr'
                         [pos=1 means: line core is located at arr(1)]

 optional output:   vel: Doppler velocity in m/s, measured from
                         center of interval, Redshift is positive

 Restrictions:     The interval may be much  wider than the line 
                   or contain only the line core. The routine works
                   for odd and even numbers of elements of 'arr'.
                   the line core intensity is NOT measured.

 Procedure:        The Fourier phase method is used. This method is 
                   very insensitive to noise and is very fast. 

(See /home/cbeck/firs_soft2/lpff.pro)

============================================================================

	procedure : makecontplot

	purpose  : Overplot contours of image array. Additional
	           options: remove short contours, fill contours,
                  create separate mask of contours, overplot contours
                  somewhere in graph.

	written :  cbeck@KIS

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 2) then begin
print
print, "usage:  makecontplot,image,levels,xy,xy_info,index_do,"
       print, "                    offsset = offsset, scale = scale,"
       print, "                  color = color, thick = thick,gband = gband,"
       print,"                  filled = filled,mask = mask,up_lim = up_lim,"
       print,"                  noplot = noplot,ps = ps,noshort = noshort,"
       print, "                 no_edge=no_edge,close = close"
print
print, "	Plot contour lines of image either filled or unfilled."
       print, "        Omit short contour lines or create mask of contours."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		image : 2-D matrix"
       print, "                levels : contour levels to be drawn"
       print, "                xy,xy_info: same as for contour"
       print, "                index_do : cf. line 217, can be used to"
       print, "                           manually remove some contours"
       print
       print, "        Keywords:"
       print, "                offsset : offset [x0,y0] of lower left corner"
       print, "                          in normal coordinates."
       print, "                scale : [nx,ny] number of images in x/y"
       print, "                        dimension."
       print, "                E.g., to overplot contours of image to"
       print, "                a set of other images, set scale = [2,1]"
       print, "                (2 images in one row), and offsset to"
       print, "                [.5,.0] to overplot on the right image."
       print, "                color,thick : as usual"
       print, "                gband : lower limit of length of contours"
       print, "                        to be excluded. E.g.: all contours"
       print, "                        with < gband vertex points will be"
       print, "                        omitted."
       print, "                /filled : fill contours using draw_poly."
       print, "                mask : named variable of same dimensions"
       print, "                       as image, will contain a mask of the"
       print, "                       contours."
       print, "                up_lim : too short contours will be taken"
       print, "                         if their mean intensity is larger"
       print, "                         than up_lim * I_surroundings"
       print, "                /no_plot : suppress plotting"
       print, "                /ps : prevents errors using device in ps-mode"
       print, "                /noshort : throw out too short contours"
       print, "                no_edge,close : see contour."
       print
       print, " To create a mask of the contours use"
       print, "    ...,gband = 15,/filled,mask = mask"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/makecontplot.pro)

============================================================================

	function : mamultsymb

	purpose  : Perform matrix multiplication of 2 symbolic matrices.

	written :  cbeck@KIS

=============================================================================

	Check number of arguments.

=============================================================================
f (n_params() lt 3) then begin
print
print, "usage:  erg = mamultsymb(a,b,xswitch)"
print
print, "	Perform standard matrix multiplication of two"
       print, "        string matrices with symbolic entries."
       print, "        Entries equal to zero will be set to zero."
       print
print, "	Arguments"
       print, "                Input :"
       print, "	        a : n x m string matrix"
       print, "	        b : m x k string matrix"
       print, "                xswich : 1 put parentheses around result"
       print, "                         0 no parentheses"
       print
       return,0
ndif
=============================================================================

(See /home/cbeck/firs_soft2/mamultsymb.pro)

============================================================================

	procedure : matrix_inversion

	purpose   : solve linear problem out = M * in by matrix inversion.
                   Result is equivalent to least square fit.

	written   : cbeck@kis 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 4) then begin
print
print, "usage:   matrix_inversion,in,out,M,errors" 
print
print, "	 Solve linear problem out = M * in. out and in must"
       print, "         have suited dimensions. Size is not checked before"
       print, "         calculations, errors may cause break."
       print, "         Example : in = rows x columns,"
       print, "         = 37x4, out = 37x4 -> M = 4x4."
       print, "         in = 37 x 4, out = 37 x 1 -> M = 4x1."
       print, "         Errors are identical for each column of M."
print
print, "	Arguments"
       print, "              Input :"
       print, "              in, out : Input and output of system, suited"
       print, "                        dimensions."
       print, "              Output :
       print, "              M      : columns_1 x columns_2 matrix M
       print, "              errors : vec(columns_1), error of columns of M"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/matrix_inversion.pro)

 calculates Mueller matrix of a mirror given rs/rp and retardance

(See /home/cbeck/firs_soft2/mirror.pro)

============================================================================

	function : mittelung

	purpose  : floating average over 3 pixel range on vector

       calls    : length.pro

	written  : cbeck@KIS 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  erg = mittelung(x)
print
print, "	Perform average over 3 pixel according to"
       print, "        x_av(k) = 1/3 * (x(k-1)+x(k)+x(k+1))"
       print
       print, "        Input:"
       print, "              x : 1-dimensional vector"
       print
       print, "        Output:"
       print, "              erg = averaged vector of same dimensions."
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/mittelung.pro)

==============================================================================

	function : num2string

	purpose  : return the value as a string without whitespaces

       calls    : strtrim.pro, strcompress.pro, string.pro (idl-implemented)

	writen   : cbeck@kis, 06/02

==============================================================================

	Check number of parameters.

==============================================================================
f n_params() ne 1 then begin
print
print, "usage:  str = num2string(value)"
print
print, "      Return 'value' as a string vector without whitespaces"
print
print, "	Arguments"
       print, "                Input :"
       print, "                value : number/vector to be converted"
       print
       print, "                Output:"
       print, "                str   : string/vector of strings"
       print
return, ''
ndif
==============================================================================

(See /home/cbeck/firs_soft2/num2string.pro)

============================================================================

 procedure : paused

 purpose   : stop until user confirms with return

 calls     : read_keyboard.pro

 keyword   : \notext : do not print standard text 'Paused. Hit return
                       to continue.'

 written   : cbeck@KIS 06/02

============================================================================

(See /home/cbeck/firs_soft2/paused.pro)

===========================================================================
 procedure : pillarheight
 
 purpose   : calculate pillar height for given date and azimuth

 calls     : r_frame_asp_mod.pro with some subroutines from ASP-lib

 written   : cbeck@kis 07/02
===========================================================================

 program call: pillarheight,azimuth,day,month,year
 
 parameters:
            azimuth: position of first coelostat mirror, east = positive 
            day,month,year: date of observation dd,mm,yy

 output    : screen, declination of sun, pillarheight

===========================================================================
f n_params() lt 4 then begin
print
print, "usage:  pillarheight,az,dd,mm,yy"
       print
print, "	Calculate needed pillar height for given azimuth of"
       print, "        first mirror and date, solar observations."
       print, "        If you want to observe another target, copy the lines"
       print, "        below line 70 and simply change declination."
     	print
print, "	Output is printed on screen."
print
print, "	Arguments"
  	print, "        Input:"
print, "	    az       : azimuth of first coelostat mirror, deg."
       print, "            dd,mm,yy : date of observation, e.g. 2,10,2"
       print
       print, "        Output:"
       print, "               screen, pillar height and sun declination"
print
       return
ndif
===========================================================================

(See /home/cbeck/firs_soft2/pillarheight.pro)

============================================================================

	procedure : plot_hist

	purpose  : Plot histogram of vector.

	written :  cbeck@KIS

=============================================================================

	Check number of arguments.

=============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  plot_hist,param,xtitle= xtitle,ytitle= ytitle,"
       print, "                  title= title,nbins = nbins,xrange = xrange,"
       print, "                  yrange = yrange,charsize= charsize,"
       print, "                  oplott = color,plot_range = plot_range,"
       print, "                  thick = thick,position = position,"
       print, "                  device = device"
print
print, "	Plot histogram of vector in nbins equidistant bins."
       print, "        Output is in percent. Allows overplot of other"
       print, "        histograms."
       print
print, "	Arguments"
       print, "                Input :"
       print, "	        param : vector of values"
       print
       print, "        Keywords:"
       print, "              xtitle,ytitle,title,thick,position: as usual"
       print, "              nbins  : number of bins"
       print, "              xrange : xrange of plot"
       print,"               yrange : range [low,high] of values in param"
       print, "                       to be considered, values outside will"
       print, "                       be neglected for the histogram."
       print, "              plot_range : range of y-axis for plot"
       print, "              oplott : number of color for an overplotted"
       print, "                       histogram. Uses oplot over existing"
       print, "                       graph."
       print
       return
ndif
=============================================================================

(See /home/cbeck/firs_soft2/plot_hist.pro)

============================================================================

	function : read_directory

	purpose  : list files in a directory. Set additional flag, if
	           filename is a directory.

       calls    : filepath.pro, fstat.pro, spawn (idl-implemented)

	written :  cbeck@KIS 06/03

=============================================================================

	Check number of arguments.

=============================================================================
f n_params() gt 1 or n_elements(help) ne 0 then begin
print
print, "usage:  erg = read_directory(inpath,help = help), or"
       print, "        erg = read_directory()"
print
       print, "        Return entries of a directory as structure."
       print, "        If argument inpath is omitted the current directory"
       print, "        is taken."
       print, "        If filenames are subdirectories, additional"
       print, "        flag is set. erg is a structure of the following"
       print, "        shape: erg = {files:strarr(n),types:strarr(n),"
       print, "                      success:fltarr(1)}. types = '0': file"
       print, "                      types ='1': directory."
       print, "                      if erg.success = 0 temporary file"
       print, "                      could not be created, or inpath was"
       print, "                      no directory."
       print, "         Only the first 2000 entries are processed."
       print, "         Number could be changed if necessary, see line 89ff."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		inpath : string of filepath to list entries"
       print, "                         of. May be omitted, current"
       print, "                         directory is taken as default in"
       print, "                         this case."
       print
       listing_inf = {files:'',types:'',success:fltarr(1)}
       return,listing_inf
ndif
=============================================================================

(See /home/cbeck/firs_soft2/read_directory.pro)

============================================================================

 function : read_keyboard

 purpose  : read user input from keyboard

 calls    : read.pro (idl-implemented), string2num.pro

 written  : cbeck@KIS 06/02

============================================================================

	Check number of arguments.

==============================================================================
f (n_elements(help) ne 0) then begin
print
print, "usage: ans = read_keyboard(text,/number,/help)"
       print
print, "	Read user input from terminal. Default output: string."
       print, "        See string2num for details on conversion if /number"
       print, "        is set."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		text  : string to be printed, may be"
       print, "                        completely omitted "
       print
       print, "                Output:"
       print, "                ans   : user input from terminal"
       print
       print, "        Keywords:"
       print, "                /number : convert input to floating number"
       print, "                          multiple input '1,2,42' allowed"
       print, "                          see string2num.pro for details"
       print, "                /help   : print this text 
       print
       return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/read_keyboard.pro)

 function retarder,axis_angle,retardance
 calculates Mueller matrix of a rotated ideal retarder

(See /home/cbeck/firs_soft2/retarder.pro)

 function rotat,phi
 calculates rotation Mueller matrix given the physical rotation angle

(See /home/cbeck/firs_soft2/rotat.pro)

	procedure:  r_frame_asp

	purpose:  translate magnetic field vector from telescope frame
		  to local solar frame.

	author:  paul@ncar

=============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	r_frame_asp $"
print, "	, psi, azm				$ ;Input"
print, "	, year, month, day, utime		$ ;Input"
print, "	, west_arcsec, north_arcsec		$ ;Input"
print, "	, local_incline, local_azimuth	      [	$ ;Output"
print, "	, ambig_incline, ambig_azimuth		$ ;Output"
print, "	, mu_value				$ ;Output"
print, "	, longitude, latitude, carlong		$ ;Output"
print, "	, right_ascen, declination, gsdt	$ ;Output"
print, "	, b0_angle, p_angle			$ ;Output"
print, "	, cen_long, radius_arcsec	      	$ ;Output"
print, "	, parallactic, hour_angle	      ]	  ;Output"
print
print, "	Translate magnetic field vector from observers"
print, "	frame to local solar frame."
print
pause, "(return to continue)"
print
print, "Arguments (input):"
print, "(all angles in radians)"
print, "(all are scalars)"
print
print, "		    psi	- inclination angle of field from"
print, "			  line-of-sight"
print, "		    azm	- field azimuth counter clockwise"
print, "			  plane of incidence of VTT elevation"
print, "			  mirror"
print, "		   year	- year of observation"
print, "			  (1900 added for 50 < year < 101 )"
print, "			  (2000 added for year < 51 )"
print, "		  month	- month of year"
print, "		    day	- day of month"
print, "		  utime	- universal time in hours"
print, "	    west_arcsec	- Arc seconds helio centric west of"
print, "			  disk center"
print, "	   north_arcsec - Arc seconds helio centric north of"
print, "			  disk center"
print
pause, "(return to continue)"
print
print, "Arguments (output):"
print, "(all angles in radians)"
print, "(all are scalars)"
print
print, "	  local_incline - field inclination in local frame"
print, "	  local_azimuth - field azimuth in local frame"
print, "			  (CCW from solar west)"
print, "	  ambig_incline - ambiguous field inclination"
print, "	  ambig_azimuth - ambiguous field azimuth
print, "	       mu_value - mu value of observation"
print, "	      longitude - longitude of observation"
print, "			  from meridian positive west"
print, "	       latitude - latitude of observation"
print, "			  from equator positive north"
print, "		carlong - carrington longitude of observation"
print, "	    right_ascen	- right ascension of disk center"
print, "	    declination	- declination of disk center"
print, "		   gsdt	- right ascension from central"
print, "			  meridian"
print, "      	       b0_angle	- b0 angle"
print, "		p_angle - p angle"
print, "	       cen_long - carrington longitude of disk center"
print, "	  radius_arcsec - solar radius in arc seconds"
print, "	    parallactic - parallactic angle CCW from earth"
print, "			  north to telescope plus elevation"
print, "	     hour_angle - hour angle at observatory"
print
pause, "(return to continue)"
print
print, "Keyword:"
print
print, "	     inst_az_el - input two valued vector with"
print, "			  azimuth and elevation at telescope
print, "			  site (def: use ephemeris)"
print, "		lapalma - set if La Palma telescope"
return
ndif

(See /home/cbeck/firs_soft2/r_frame_asp.pro)

	procedure:  r_frame_asp

	purpose:  translate magnetic field vector from telescope frame
		  to local solar frame.

	author:  paul@ncar

=============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	r_frame_asp $"
print, "	, psi, azm				$ ;Input"
print, "	, year, month, day, utime		$ ;Input"
print, "	, west_arcsec, north_arcsec		$ ;Input"
print, "	, local_incline, local_azimuth	      [	$ ;Output"
print, "	, ambig_incline, ambig_azimuth		$ ;Output"
print, "	, mu_value				$ ;Output"
print, "	, longitude, latitude, carlong		$ ;Output"
print, "	, right_ascen, declination, gsdt	$ ;Output"
print, "	, b0_angle, p_angle			$ ;Output"
print, "	, cen_long, radius_arcsec	      	$ ;Output"
print, "	, parallactic, hour_angle	      ]	  ;Output"
print
print, "	Translate magnetic field vector from observers"
print, "	frame to local solar frame."
print
pause, "(return to continue)"
print
print, "Arguments (input):"
print, "(all angles in radians)"
print, "(all are scalars)"
print
print, "		    psi	- inclination angle of field from"
print, "			  line-of-sight"
print, "		    azm	- field azimuth counter clockwise"
print, "			  plane of incidence of VTT elevation"
print, "			  mirror"
print, "		   year	- year of observation"
print, "			  (1900 added for 50 < year < 101 )"
print, "			  (2000 added for year < 51 )"
print, "		  month	- month of year"
print, "		    day	- day of month"
print, "		  utime	- universal time in hours"
print, "	    west_arcsec	- Arc seconds helio centric west of"
print, "			  disk center"
print, "	   north_arcsec - Arc seconds helio centric north of"
print, "			  disk center"
print
pause, "(return to continue)"
print
print, "Arguments (output):"
print, "(all angles in radians)"
print, "(all are scalars)"
print
print, "	  local_incline - field inclination in local frame"
print, "	  local_azimuth - field azimuth in local frame"
print, "			  (CCW from solar west)"
print, "	  ambig_incline - ambiguous field inclination"
print, "	  ambig_azimuth - ambiguous field azimuth
print, "	       mu_value - mu value of observation"
print, "	      longitude - longitude of observation"
print, "			  from meridian positive west"
print, "	       latitude - latitude of observation"
print, "			  from equator positive north"
print, "		carlong - carrington longitude of observation"
print, "	    right_ascen	- right ascension of disk center"
print, "	    declination	- declination of disk center"
print, "		   gsdt	- right ascension from central"
print, "			  meridian"
print, "      	       b0_angle	- b0 angle"
print, "		p_angle - p angle"
print, "	       cen_long - carrington longitude of disk center"
print, "	  radius_arcsec - solar radius in arc seconds"
print, "	    parallactic - parallactic angle CCW from earth"
print, "			  north to telescope plus elevation"
print, "	     hour_angle - hour angle at observatory"
print
pause, "(return to continue)"
print
print, "Keyword:"
print
print, "	     inst_az_el - input two valued vector with"
print, "			  azimuth and elevation at telescope
print, "			  site (def: use ephemeris)"
print, "		lapalma - set if La Palma telescope"
print, "		azimuth - returned solar azimuth"
print, "	      elevation - returned solar elevation"
return
ndif

(See /home/cbeck/firs_soft2/r_frame_asp_mod.pro)

	function:  r_frame_julian

	purpose:  compute Julian time including fraction of day.

	author:  paul@ncar

=============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	djd = r_frame_julian( year, month, day, utime )"
print
print, "	Return double precision Julian time including"
print, "	fraction of day."
print
print, "	Arguments:"
print, "		   year	- year of observation"
print, "			  (1900 added for 50 < year < 101 )"
print, "			  (2000 added for year < 51 )"
print, "		  month	- month of year"
print, "		    day	- day of month"
print, "		  utime	- universal time in hours"
return, 0
ndif

(See /home/cbeck/firs_soft2/r_frame_julian.pro)

	procedure:  r_frame_solcor

	purpose:  do solar ephemeris

	authors:  unknown@somewhere  paul@ncar

=============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	r_frame_solcor"
print, "	,   julian_time 		[$ ;Input"
print, "	,   right_ascen [, declination	[$ ;Output"
print, "	,          gsdt [,    b0_angle	[$ ;Output"
print, "	,       p_angle [,    cen_long	[$ ;Output"
print, "	, radius_arcsec ]]]]]]]		   ;Output"
print
print, "	Do solar ephereris"
print
print, "Arguments:"
print, "(all angles in radians)"
print, "(all are scalars)"
print
print, "	    julian_time	- julain time in days including
print, "			  fraction of days.
print, "			  (Recommend double precision).
print, "	    right_ascen	- right ascension of disk center"
print, "	    declination	- declination of disk center"
print, "		   gsdt	- right ascension from central"
print, "			  meridian"
print, "      	       b0_angle	- b0 angle"
print, "		p_angle - p angle"
print, "	       cen_long - carrington longitude of disk center"
print, "	  radius_arcsec - solar radius in arc seconds"
return
ndif

(See /home/cbeck/firs_soft2/r_frame_solcor.pro)

	procedure:  r_frame_sphduo

	purpose:  translate unit vector form one local longitude,latitude
		  frame to another local longitude,latitude frame.

	author:  paul@ncar

==============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	r_frame_sphduo $"
print, "	, lng0, lat0, az0, el0 $"
print, "	, lng3, lat3, az3, el3
print
print, "	Translate unit vector form one local longitude,"
print, "	latitude frame to another local longitude,latitude"
print, "	frame."
print
print, "	Input:"
print, "
print, "		lng0	- longitude of input reference frame"
print, "			  (right handed (increasing to right"
print, "			  if north is up))"
print, "		lat0	- latitude of input reference frame"
print, "			  (positive to north)"
print, "		az0	- azimuth of input unit vector"
print, "			  (right handed (CCW from north))"
print, "		el0	- elevation of input unit vector"
print, "			  (positive to increasing az0 axis)"
print
print, "		lng3	- longitude of output reference frame"
print, "			  (right handed (increasing to right"
print, "			  if north is up))"
print, "		lat3	- latitude of output reference frame"
print, "			  (positive to north)"
print
print, "	Output:"
print, "
print, "		az3	- azimuth of output unit vector"
print, "			  (right handed (CCW from north))"
print, "		el3	- elevation of output unit vector"
print, "			  (positive to increasing az3 axis)"
print
return
ndif

(See /home/cbeck/firs_soft2/r_frame_sphduo.pro)

	procedure:  r_frame_sphtri

	purpose:  Transform a unit vector between two spherical
		  reference points.

	reference:  Fundamental spherical trigonometry equations from Smart:
		    Text-Book on Spherical Astronomy, eq. A, B, C, and D.

	authors:  kcjones@sunspot.noao.edu (Phil Wiborg),   paul@ncar

=============================================================================

	Check number of parameters.

f  n_params() lt 5  then begin
print
print, "usage:	r_frame_sphtri0 $"
print, "	, olat		$ ;Input"
print, "	, az0, el0	$ ;Input"
print, "	, az1, el1    [	$ ;Output"
print, "	, para	      ]	  ;Output"
print
print, "	Transform a unit vector between two spherical"
print, "	reference points."
print
print, "	Definition:"
print
print, "		sct0	~ The great circle sector that"
print, "			  connects the two reference points"
print, "			  on the sphere"
print
print, "	Arguments (all in radians):"
print
print, "		olat	- !pi/2.-abs(sct0)"
print, "		az0	- The azimuth about first reference"
print, "			- point, from sector sct0"
print, "		el0	- The elevation at first reference"
print, "			  point, positive away from surface"
print, "		az1	- The azimuth about second reference"
print, "			  point, from sector sct0"
print, "		el1	- The elevation at second reference"
print, "			  point, positive away from surface"
print, "		para	- In dircetion of the unit vector"
print, "			  in a plane perpendicular to"
print, "			  the unit vector, the angle CCW from"
print, "			  projected axis of first reference"
print, "			  point to projected axis of the"
print, "			  second reference point"
print
print, "	Note: If az0 is positive CCW, the az1 is positive CCW"
print, "	      If az0 is positive  CW, the az1 is positive  CW"
print
print, "The routine can be used to convert between coordinate"
print, "systems as follows:"
print
print, "(1) Let: az0 = hour angle      (2) Let: az0 = azimuth"
print, "         el0 = declination              el0 = elevation"
print, "        olat = earth latitude          olat = earth latitude"
print
print, "   Then: az1 = azimuth            Then: az1 = hour angle"
print, "         el1 = elevation                el1 = declination"
print, "        para = parallatic              para = neg. parallatic"
print, " 	       (positive counter"
print, "	       clockwise from"
print, "	       earth north)"
print
return
ndif

(See /home/cbeck/firs_soft2/r_frame_sphtri.pro)

	procedure:  r_frame_sphtri0

	purpose:  Transform a unit vector between two spherical
		  reference points.
		  (Same effect as r_frame_sphtri but does not do
		  parallactic angle).

	reference:  Fundamental spherical trigonometry equations from Smart:
		    Text-Book on Spherical Astronomy, eq. A, B, C, and D.

	authors:  kcjones@sunspot.noao.edu (Phil Wiborg),   paul@ncar

=============================================================================

	Check number of parameters.

f  n_params() lt 5  then begin
print
print, "usage:	r_frame_sphtri0 $"
print, "	, olat		$ ;Input"
print, "	, az0, el0	$ ;Input"
print, "	, az1, el1	  ;Output"
print
print, "	Transform a unit vector between two spherical"
print, "	reference points."
print, "	(Same effect as r_frame_sphtri but does not do"
print, "	parallactic angle)."
print
print, "	Definition:"
print
print, "		sct0	~ The great circle sector that"
print, "			  connects the two reference points"
print, "			  on the sphere"
print
print, "	Arguments (all in radians):"
print
print, "		olat	~ !pi/2.-abs(sct0)"
print, "		az0	~ The azimuth about first reference"
print, "			  point, from sector sct0"
print, "		el0	~ The elevation at first reference"
print, "			  point, positive away from surface"
print, "		az1	~ The azimuth about second reference"
print, "			  point, from sector sct0"
print, "		el1	~ The elevation at second reference"
print, "			  point, positive away from surface"
print
print, "	Note: If az0 is positive CCW, the az1 is positive CCW."
print, "	      If az0 is positive  CW, the az1 is positive  CW."
print
print, "The routine can be used to convert between coordinate"
print, "systems as follows:"
print
print, "(1) Let: az0 = hour angle      (2) Let: az0 = azimuth"
print, "         el0 = declination              el0 = elevation"
print, "        olat = earth latitude          olat = earth latitude"
print
print, "   Then: az1 = azimuth            Then: az1 = hour angle"
print, "         el1 = elevation                el1 = declination"
print
return
ndif

(See /home/cbeck/firs_soft2/r_frame_sphtri0.pro)

	procedure:  r_frame_sun

	purpose:  From time, hilio centric (west,north) arc seconds on sun
		  find solar longitude and latitude.

	author:  paul@ncar

=============================================================================

	Check number of parameters.

f n_params() eq 0 then begin
print
print, "usage:	r_frame_sun			$"
print, "	, year, month, day, utime 	$ ;Input"
print, "	, west_arcsec, north_arcsec	$ ;Input"
print, "	, longitude, latitude		$ ;Output"
print, "	, mu_value		      [	$ ;Output"
print, "	, right_ascen, declination    	$ ;Output"
print, "	, gsdt, b0_angle, p_angle	$ ;Output"
print, "	, cen_long, radius_arcsec     ]	  ;Output"
print
print, "	From time, hilio centric (west,north) arc seconds on"
print, "	sun find solar longitude and latitude.
print
print, "	Arguments:"
print
print, "		   year	- year of observation"
print, "			  (1900 added for 50 < year < 101 )"
print, "			  (2000 added for year < 51 )"
print, "		  month	- month of year"
print, "		    day	- day of month"
print, "		  utime	- universal time in hours"
print, "	    west_arcsec	- Arc seconds helio centric west of"
print, "			  disk center"
print, "	   north_arcsec - Arc seconds helio centric north of"
print, "			  disk center"
print, "	      longitude - longitude positive west of solar"
print, "			  line of sight meridian"
print, "	       latitude - latitude positive north of solar"
print, "			  equator"
print, "	       mu_value - observation mu value"
print, "	    right_ascen	- right ascension of disk center"
print, "	    declination	- declination of disk center"
print, "		   gsdt	- right ascension from central"
print, "			  meridian"
print, "      	       b0_angle	- b0 angle"
print, "		p_angle - p angle"
print, "	       cen_long - carrington longitude of disk center"
print, "	  radius_arcsec - solar radius in arc seconds"
return
ndif

(See /home/cbeck/firs_soft2/r_frame_sun.pro)

  function:  setmtxright

  purpose:  Return 4x4 matrix set with argument list.
	     Note a transpose is done to get matrix operations
	     to work as one would expect.

  author:  paul seagraves 92.09.03
  edited : cbeck 2001
==============================================================================

	Check number of parameters.

f n_params() ne 16 then begin
print
print, "usage:  m = setmtxright (e00, e01, e02, e03, $"
print, "	            e10, e11, e12, e13, $"
print, "	            e20, e21, e22, e23, $"
print, "	            e30, e31, e32, e33)"
print
print, "	Return 4x4 matrix set with argument list."
print
return, 0
ndif

(See /home/cbeck/firs_soft2/setmtxright.pro)

 NAME:
       SHC
 PURPOSE:
       Find the linear shift between two 2-d images using the
       forier crosscorrelation method and optional interpolation for
       sub-pixel shifts.
 CATEGORY:

 CALLING SEQUENCE:
       RESULT = SHC ( IMG1, IMG2 )
 INPUTS:
       IMG1,IMG2 : 2-d arrays of same size
 KEYWORDS:
       FILTER : (Flag) if set and not zero, an edge filter is used
                for the fft.
   INTERPOLATE: (Flag) If set and not zero, interpolate the position
                of the maximum of the cross correlation function to
                sub-pixel accuracy.
 OUTPUTS:
       RESULT : 2-element vector with the shift of IMG2 relative to
                IMG1. RESULT(0) is shift in X-direction, RESULT(1) is
                shift in Y-direction.
 PROCEDURE:
       Compute the crosscorrelation function using FFT and locate the
       maximum.
 MODIFICATION HISTORY:
       13-Aug-1992  P.Suetterlin, KIS
       29-Aug-1995  PS Added Edge filter
       30-Aug-1995  PS Add Subpix interpolation. Slight rewrite of
                    normal maximum finding (Use shift)
       11-Sep-1995  PS: Forgot the 1-d case. Re-implemented.

(See /home/cbeck/firs_soft2/shc.pro)

 NAME SHIFT_FRAC
	
 PURPOSE: 
       Shift an 2-d image by fractional pixels in x and y direction,
	either by bilinear or bicubic interpolation.
*CATEGORY:            @CAT-# 16 18@
       Image Processing , Interpolation
 CALLING SEQUENCE:
	result = SHIFT_FRAC (image, dx,dy [, {'L' | 'C'} ] [,MISSING=missing] )
 INPUTS:
	image: the 2-dim image array to be shifted.
       dx, dy: the shift to be done in 1st ("x") and 2nd ("y") dimension
              of the image. If positive, the shift is done towards right
              or upper direction. 
 OPTIONAL INPUT:
	method: string specifying the interpolation method;
              either = 'L': bilinear interpolation (the default)
              or     = 'C': cubic interpolation.
 KEYWORD PARAMETERS:
       MISSING=missing: The value to return for elements outside the bounds 
              of array image. 
              Default: Interpolated positions that fall outside the bounds of
              the image, are set to the value of the nearest image pixel. 
 OUTPUTS:
	Array with the shifted image. Same size as input image array.
	
 PROCEDURE:
	Calls IDL-function INTERPOLATE.

 MODIFICATION HISTORY:
	nlte&kis, 2000-Jul-05

(See /home/cbeck/firs_soft2/shift_frac.pro)

============================================================================

	procedure : shift_img

	purpose  :  shift image row by row for amount in shift_vec

       calls    :  shift_frac.pro
 
	written  :  cbeck@kis 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 4) then begin
print
print, "usage:  shift_img,img,shift_vec,firsty,lasty
print
print, "	Shift image row by row for amount in shift_vec."
print
print, "	Arguments"
       print, "                Input :"
print, "		img       : image to be shifted"
       print, "                shift_vec : amount to be shifted in pixel,"
       print, "                            length must correspond with"
       print, "                            firsty,lasty"
       print, "                firsty,lasty : useable range along slit"
print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/shift_img.pro)

============================================================================

	procedure : sshift_img

	purpose  :  shift image row by row for amount in shift_vec

       calls    :  shift_frac.pro
 
	written  :  cbeck@kis 06/02

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 4) then begin
print
print, "usage:  sshift_img,img,shift_vec,firsty,lasty
print
print, "	Shift image row by row for amount in shift_vec."
print
print, "	Arguments"
       print, "                Input :"
print, "		img       : image to be shifted"
       print, "                shift_vec : amount to be shifted in pixel,"
       print, "                            length must correspond with"
       print, "                            firsty,lasty"
       print, "                firsty,lasty : useable range along slit"
print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/sshift_img.pro)

==============================================================================

	function :  string2num

	purpose  :  return the value of a string as double if possible
                   takes whitespace, '/', ',' or ':' as separator

       calls    : strsplit.pro, strtrim.pro, strcompress.pro,
                  double.pro, where.pro (idl-implemented),
                  length.pro, num2string.pro

       written  :  cbeck@KIS 06/02

==============================================================================

	Check number of parameters.

==============================================================================
f n_params() ne 1 then begin
print
print, "usage:  num = string2num(str, /verbose )"
print
print, "      Return content of a string as double precision floating."
       print, "      Returns vector, if more than one number seperated"
       print, "      by blanks or  /,;: is found."
       print, "      Attention : The number 42424242424242.42 will be cut"
       print, "      out of the string, so be careful with that number !!"
       print, "      If no number or ONLY '42424242424242.42' is found, the"
       print, "      the output is the string 'nonumber' ."
print
       print, "	Arguments"
       print, "                Input :"
       print, "		str   : string, may contain more than one"
       print, "                        number."
       print
       print, "                Output:"
       print, "                num   : number/vector of numbers."
       print
       print, "        Keywords:"
       print, "                /verbose : give additional run time info"
       print
       print, "        Example: str = '12,324:55.34,abcd76 45' gives"
       print, "        res=[12,324,55.34,45]"
       print, "        while str = '12,324:55.34,76abcd 45' gives"
       print, "        res=[12,324,55.34,76,45]"
       print
return,0
ndif
==============================================================================

(See /home/cbeck/firs_soft2/string2num.pro)

 NAME:
       UNIQUE
 PURPOSE:
       Return the unique elements of an array.
 CATEGORY:
 CALLING SEQUENCE:
       out = unique(in, count)
 INPUTS:
       in = input array to process.                    in
 KEYWORD PARAMETERS:
       Keywords:
         /SORT means sort array before selecting unique elements.
 OUTPUTS:
       out = returned unique elements from in.         out
       count = cw# occurances of each unique element.  out
 COMMON BLOCKS:
 NOTES:
       Notes: unsorted arrays only have repeated elements
         dropped, use /SORT to drop all extra repeated elements.
 MODIFICATION HISTORY:
       R. Sterner, 4 Oct, 1993
       R. Sterner, 5 Oct, 1993 --- added count.

 Copyright (C) 1993, Johns Hopkins University/Applied Physics Laboratory
 This software may be used, copied, or redistributed as long as it is not
 sold and this copyright notice is reproduced on each copy made.  This
 routine is provided as is without any express or implied warranties
 whatsoever.  Other limitations apply as described in the file disclaimer.txt.

(See /home/cbeck/firs_soft2/unique.pro)

 NAME: 
     VALID_NUM()
 PURPOSE:               
     Check if a string is a valid number representation.
 EXPLANATION:              
     The input string is parsed for characters that may possibly
     form a valid number.  It is more robust than simply checking
     for an IDL conversion error because that allows strings such
     as '22.3qwert' to be returned as the valid number 22.3

     This function had a major rewrite in August 2008 to use STREGEX
     and allow vector input.    It should be backwards compatible.
 CALLING SEQUENCE: 
     IDL> status = valid_num(string  [,value]  [,/integer])
    
 INPUTS:
     string  -  the string to be tested, scalar or array
               
 RETURNS
     status - byte scalar or array, same size as the input string
              set to 1 where the string is a  valid number, 0 for invalid
 OPTIONAL OUTPUT:               
     value     - The value the string decodes to, same size as input string.
           This will be returned as a double precision number unless 
           /INTEGER is present, in which case a long integer is returned.
           
 OPTIONAL INPUT KEYWORD:          
    /INTEGER   -  if present code checks specifically for an integer.
 EXAMPLES:
     (1) IDL> print,valid_num(3.2,/integer) 
        --> 0     ;Since 3.2 is not an integer 
     (2) IDL> str =['-0.03','2.3g', '3.2e12']
         IDL> test = valid_num(str,val)
              test = [1,0,1]    &  val =  [-0.030000000 ,NaN ,3.2000000e+12]
 REVISION HISTORY:
          Version 1, C D Pike, RAL, 24-May-93
          Version 2, William Thompson, GSFC, 14 October 1994
                       Added optional output parameter VALUE to allow
                       VALID_NUM to replace STRNUMBER in FITS routines.
          Version 3 Wayne Landsman rewrite to use STREGEX, vectorize
          Version 4 W.L. (fix from C. Markwardt) Better Stregex expression, 
                    was missing numbers like '134.' before Jan 1 2010

(See /home/cbeck/firs_soft2/valid_num.pro)

============================================================================

	function : vecnorm

	purpose  : calculate absolute length of 3-D vector

	written :  cbeck@KIS

=============================================================================

	Check number of arguments.

=============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  erg = vecnorm(x)"
print
print, "	Calculate length of 3-D vector."
       print
print, "	Arguments"
       print, "                Input :"
       print, "	        x :  vector with [x1,x2,x3]"
       print
       return,0
ndif
=============================================================================

(See /home/cbeck/firs_soft2/vecnorm.pro)

==============================================================================

	function :  vtt_ten

	purpose  :  return the unnormalized telescope matrix for the
		    vacuum tower telescope Teneriffa

       written  :  cbeck@kis, 12/01

==============================================================================

       Check number of parameters.

==============================================================================
f n_params() lt 24 then begin
print
print, "usage:	T = vtt_ten( th1, th2, th3          $"
print, "                     , winret, winang       $"
print, "                     , exret, exang         $"
print, "                     , offout               $"
print, "                     , coel1rs,coel1rp,coel1ret$"
print, "                     , coel2rs,coel2rp,coel2ret$"
print, "                     , prirs, prirp, priret,xi$"
       print, "                     , th_pol_C1,th_C1_pol,th_pol_C2,"
       print, "                     , /polarizer, /ideal )"
print
print, "        Return the 4x4 vacuum tower telescope matrix."
       print	
print, "	Arguments"
       print, "                th1     : rotation angle between RF0 and first"
       print, "                          coelostat mirror"
       print, "                th2     : rotation angle between C1 and C2"
       print, "                th3     : rotation angle between C2 and main"
       print, "                winret  : retardance of entry window"
       print, "                winang  : position angle of entry window"
       print, "                exret   : retardance of exit window"
       print, "                exang   : position angle of exit window"
       print, "                offout  : rotation between deflection mirror"
       print, "                          and polarimeter fiducial axis"
       print, "                coel1rs : reflectivity perpendicular to plain"
       print, "                          of incidence, C1"
       print, "                coel1rp : reflectivity in the plain of"
       print, "                          incidence, C1"
       print, "                coel1ret: retardance of first mirror C1"
       print, "                coel2rs : reflectivity perpendicular to plain"
       print, "                          of incidence, C2"
       print, "                coel2rp : reflectivity in the plain of"
       print, "                          incidence, C2"
       print, "                coel2ret: retardance of second mirror C2"
       print, "                prirs   : reflectivity perpendicular to plain"
       print, "                          of incidence, main and deflection"
       print, "                prirp   : reflectivity in the plain of"
       print, "                          incidence, main and deflection"
       print, "                priret  : retardance of main and deflection"
       print, "                          mirror"
       print, "                xi     : position angle of polarizer"
       print, "                on window: W to N, on C1: N to E"
       print, "                th_pol_C1 : rotation between polarizer and C1"
       print, "                th_C1_pol : rotation between reflected C1 and"
       print, "                            linear polarizer"
       print, "                th_pol_C2 : rotation between polarizer and C2"
print
       print, "       Keywords"
       print, "                /ideal : use ideal mirrors diag(1,1,-1,-1)"
       print, "                polarizer = 1 : put polarizer on C1"
       print, "                polarizer = 2 : put polarizer on window"
       print
       print, "       Important : all angles have to be given in degrees !"
       print
return,0
   endif
=============================================================================

(See /home/cbeck/firs_soft2/vtt_ten.pro)

============================================================================

	procedure : wave_shift

	purpose  : calculate position of line cores for images ia and ib,
	           fit polynomial of 2nd order on curve, shift all
	           images of ib,qb,ub,vb for differences of the
	           polynomials, repeat procedure 
 
       calls    : lpff.pro, sshift_img.pro

       Hardwired: offsets of CA spectrally and spatially, line
       64f. This has to be modified, if CA data is 'good',
       i.e. hairline can be detected and spectral lines in the part
       beams are not far displaced.

	written  : cbeck@kis 4/03

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 10) then begin
print
print, "usage:  wave_shift,ia,ib,qb,ub,vb,ilo,ihi,firsty,lasty"
       print, "                  ,repetitions,plt=plt"
print
print, "	Shift all images (I,Q,U,V) to minimal difference of"
       print, "        line core postions of spectral line in I."
print
print, "	Arguments"
       print, "                Input :"
print, "		ia,ib     : Stokes I intensity images A/B"
       print, "                qb,ub,vb  : polarization images of B"
       print, "                ilo,ihi   : range of spectral line to be"
       print, "                            used in aligning"
       print, "                firsty,lasty : useable range along slit"
       print, "                repetitions  : number of iterative repetitions"
       print, "                               to improve accuracy"
       print
       print, "        Keywords"
       print, "                plt      : plot line cores before and"
       print, "                           after shift"
       print, "                hairs    : if set, shift only once by the"
       print, "                           value of hairs(CA data)"
       print, "                straight : use straight line instead of"
       print, "                           polynomial of 2nd degree"
print
       print, "        Additional : for CA first shift in spectral dimension"
       print, "                     is value of filt_stepsz from op. header"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/wave_shift_firs.pro)

============================================================================

	procedure : wave_shift

	purpose  : calculate position of line cores for images ia and ib,
	           fit polynomial of 2nd order on curve, shift all
	           images of ib,qb,ub,vb for differences of the
	           polynomials, repeat procedure 
 
       calls    : lpff.pro, sshift_img.pro

       Hardwired: offsets of CA spectrally and spatially, line
       64f. This has to be modified, if CA data is 'good',
       i.e. hairline can be detected and spectral lines in the part
       beams are not far displaced.

	written  : cbeck@kis 4/03

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 10) then begin
print
print, "usage:  wave_shift,ia,ib,qb,ub,vb,ilo,ihi,firsty,lasty"
       print, "                  ,repetitions,plt=plt"
print
print, "	Shift all images (I,Q,U,V) to minimal difference of"
       print, "        line core postions of spectral line in I."
print
print, "	Arguments"
       print, "                Input :"
print, "		ia,ib     : Stokes I intensity images A/B"
       print, "                qb,ub,vb  : polarization images of B"
       print, "                ilo,ihi   : range of spectral line to be"
       print, "                            used in aligning"
       print, "                firsty,lasty : useable range along slit"
       print, "                repetitions  : number of iterative repetitions"
       print, "                               to improve accuracy"
       print
       print, "        Keywords"
       print, "                plt      : plot line cores before and"
       print, "                           after shift"
       print, "                hairs    : if set, shift only once by the"
       print, "                           value of hairs(CA data)"
       print, "                straight : use straight line instead of"
       print, "                           polynomial of 2nd degree"
print
       print, "        Additional : for CA first shift in spectral dimension"
       print, "                     is value of filt_stepsz from op. header"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/wave_shift_spinor.pro)

============================================================================

	procedure : window_pos

	purpose  : return coordinates in 2-d array

	written :  cbeck@KIS 03/04

==============================================================================

	Check number of arguments.

==============================================================================
f (n_params() lt 1) then begin
print
print, "usage:  window_pos,image,winindex = winindex,no_del = no_del"
print
print, "	Display 2-d array in window, print cursor"
       print, "        position, give position on terminal if"
       print, "        left mouse button is pressed. Right"
       print, "        mouse button finishes."
       print
print, "	Arguments"
       print, "                Input :"
       print, "		image: 2-d array"
       print
       print, "        Keywords:"
       print, "                windex : number of window, default: 0"
       print, "                no_del : keep window"
       print
       return
ndif
==============================================================================

(See /home/cbeck/firs_soft2/window_pos.pro)