TORUS1:[GLL_RAW.INFO]HOW_TO_COMPILE_GGGS.DOC

		June  2, 1999  Patrick Shriver

       updated: June 14, 1999 ps
		July 19, 1999 ps added star table info
	        July 21, 1999 ps added buffer info

==============================================================================
Compiling GGGS

The GGGS logicals (contained in DISKK:[GWIZ]GGGS_LOGICALS*_*.COM) define 
the command "gggs" to point to the executable FORTRAN routine: 
			DISKK:[GWIZ]RUN_GGGS.EXE
This FORTRAN routine then executes the commands to run the IDL program: 
			GGGS$DIR:RUN_GGGS.PRO  
RUN_GGGS.PRO will then restore the GGGS routines which have been saved into 
the file (via the IDL "SAVE" command):
			GGGS$DIR:GGGS_COMPILE.DAT

When changes are made to the GGGS routines, it is necessary to "recompile" 
the routines with the new changes into the above file.  The following steps
illustrate how to do this.

	1) run IDL in the GGGS$DIR where the changes in the routines were made
			GGGS$DIR>>idl
	2) run GGGS (by executing the @GGGS command at the IDL prompt)
			IDL> @GGGS
	3) after the GGGS widgets come up, exit out of GGGS under the
	   main menu options, back to the GGGS prompt
			GGGS>
	4) save the currently compiled routines
			GGGS> save,file='gggs_compile.dat',/routines

Now whenever the command "gggs" is run at the VAX prompt, the new changes to 
the GGGS routines will be executed.

Note that when the version of IDL is updated it may be necessary to recompile
GGGS under the new version.  (Changes to how the save files work can change
from IDL old version to new version.)

==============================================================================
GGGS Star Table

GGGS uses information stored in a star table data file to draw the stars in
the plot window.  The star table data file is stored as an IDL binary save 
file.  This save file contains the variable structure:
       			SAO number --  Star_Table.SAO
       			Star Name  --  Star_Table.Name
       			V Mag      --  Star_Table.Mag
       			type       --  Star_Table.Sp
       			RA         --  Star_Table.Ra
       			DEC        --  Star_Table.Dec
GGGS will restore this variable structure in the routine GGGS_DRAW_STARS.PRO.
The data file must have the name of:  STAR_TABLE_J2000.DAT.

Since different versions of IDL may have different formats for the 
save/restore files, it may be necessary to recreate the star table data file.
The program GGGS_SAVE_STAR_TABLE can be used to read and store the star 
information from a text file into the binary file.  The input text file must 
have a format of {SAO number, name, v mag, type, ra (deg), dec (deg)}.

ex-
 
{      147059  2    Cet      4.55000  B9.5Vn              0.295200     -17.6145}
{       10954  9    Cas      5.88000  A1III               0.409200      62.00961}


  etc.

!Note that there must not be any header information for the input file to 
GGGS_SAVE_STAR_TABLE!  

A full star table text file can be found in:
		torus1:[gll_raw.info]sao_star_table.lis
		gggs$data:sao_star_table.lis
If these *.lis files cannot be found/do not exist, it is possible to
create the file by printing out the structure array variable Star_Table.
This is can be accomplished by uncommenting the following line in
GGGS_DRAW_STARS.PRO:

; uncomment the following line in order to access the star table manually
;                                               --ps 7/21/99
;stop

and then recompiling GGGS.


A sample run of GGGS_SAVE_STAR_TABLE:
-------------------------------------
GWIZ.GGGS_2_6.SOURCE>>idl
 
IDL Version 5.0.3 (vms vax). Research Systems, Inc.
Installation number: 100-0.
Licensed for use by: glluvs
 
For basic information, enter "IDLInfo" at the IDL> prompt.
 
 
IDL> .r gggs_save_star_table
% Compiled module: SAVE_STAR_TABLE.
IDL> save_star_table
 
 
 opening input file DISKK:[GWIZ.GGGS_2_6.DATA]SAO_STAR_TABLE.LIS;2
 
 created DISKK:[GWIZ.GGGS_2_6.DATA]STAR_TABLE_J2000.DAT

IDL> 

==============================================================================
GGGS buffer overflow

When a GGGS buffer overflow error occurs, it is possible to resize the
buffers by editing the corresponding structure variable in GGGS_MAIN.PRO.