Making Finding Charts using widl

Making Finding Charts
With WIDL

widl is a package of idl procedures written to create finding charts from FITS file data. It is designed to be used with the output of getimage.and is available only on saturn. See also opchart, a Perl script written by Emilio Falco and Norm Grogin to create a label page for each set of four finding charts.

Before You Start

Set up the proper paths to access IDL and this program:

	setenv WIDL_STARTUP /home/jshaw/chart/xspam.ini
	alias widl "idl $WIDL_STARTUP"
	setenv IDL_DIR  /opt/idl/idl_5.5    # latest IDL version (currently 5.5)
	setenv IDL_PATH \+$IDL_DIR/lib:\+$IDL_DIR/user_contrib
        [the plus sign will find routines in the subdirectories]

Example

cd to the directory where your FITS files are to be located.
Use getimage, redirecting the output to this directory as follows:
```
	getimage -r [FITS directory]
```
Type widl to start the IDL process.
At the XSPAM prompt, type:
```
	makeps,/fits,/invert,/label
```
This invokes the makeps procedure to make postscript files with labels, color inverted, using FITS files as input. For each *.fits file in the directory, a *.ps postscript file will be created.
Exit widl by typing "exit".
Print the *.ps files on a postscript printer.

Remarks:

To make 4 charts per page, type:

	makeps4,/fits,/invert,/label

For every 4 FITS files in the directory, one *.ps file will be created and then psnup will be run to convert the postscript file to one with four images per page whose file name will start with "4". With makeps4, you can use a file for input by specifying list:

	makeps4,/fits,/invert,/label,/list

This will process only the fits files listed in a file called "fits.list", not all the files in the directory.

For four charts per page, print only the 4*.ps files.

To control the intensity levels in the plot, use makepsint:

	makepsint,/fits,/invert,/label,newdatamin=1000,newdatamax=5000

Color Map Error

Sometimes you will get the following error when running widl:

XSPAM 2.1> makeps,/fits,/invert,/label
% Attempt to subscript R with  is out of range.
% Execution halted at:  OVERLAYCT          36
  /home/jshaw/chart/pro/overlayct.pro
%                       MAKEPS             54 /home/jshaw/chart/pro/makeps.pro
%                       $MAIN$
XSPAM 2.1>

This generally indicates that your colormap has become corrupted. Try exiting color-intensive applications (like Netscape) and then start widl again. If that doesn't fix it, exit openwin and then try again.

Undefined procedure error

Note: makeps uses the IDL Astronomy Library routines which are now stored in subdirectories of /opt/idl/idl_5.5/user_contrib/astron/pro.

Your IDL_PATH environment variable should include \+$IDL_DIR/user_contrib/astron/pro (the plus sign will find routines in the subdirectories) to work correctly.

Last modified on April 18, 2002
dmink@cfa.harvard.edu