/*****************************************************************/
/**                                                             **/
/**                Linux Installation of DISGCL                 **/
/**                                                             **/
/** Contents: 1.) Introduction                                  **/
/**           2.) Installation of DISGCL                        **/
/**           3.) FTP Sites.                                    **/
/**                                                             **/
/** Date   : 09.10.1997                                         **/
/** Version: 2.2    / DISGCL, Linux                             **/
/** Author : Helmut Michels, Tel.: +49 5556 979 334             **/
/**          MPI fuer Aeronomie, Max-Planck-Str. 2,             **/
/**          D-37191 Katlenburg-Lindau, Germany                 **/
/** Mail:    michels@linmpi.mpg.de                              **/
/*****************************************************************/

1.) Introduction

   The graphics command language DISGCL is an  interpreter based on
   the graphics software DISLIN. All DISLIN statements can be writ-
   ten to a script file and then be executed with DISGCL, or can be
   entered  in an interactive mode.

   Similar to  programming languages  such as Fortran and C,  high-
   level language elements can be used within DISGCL. These are va-
   riables, operators, expressions, array operations, loops, if and
   switch statements,  user-defined subroutines and functions,  and
   file I/O routines.

   An easy to use interface for data input is given to include data
   into DISGCL jobs.  The format of  data files  is very simple and
   useful for most DISLIN plotting routines.

   Several  quickplots are offered by  DISGCL which are collections
   of DISLIN statements to display data with one command.
   
   Notes: 

    - Normally, DISGCL is included in the  UNIX versions of DISLIN.
      Since the  DISLIN Motif utilities for Linux are linked static
      and need a lot of space, DISGCL is placed into separate files. 

    - Additional to DISGCL, DISLIN should be installed for Linux.
      The utility programs  'disdrv',  'dishlp'  and  'disman' are
      parts of the DISLIN distribution and not included in GCL.   

    - This version of DISGCL is free software;  you can make copies
      and redistribute it. The software is distributed in the hope
      that it will be useful, but WITHOUT ANY WARRANTY.


2.) Installation of DISGCL

a) Uncompress the tar.gz file with the command

                  gzip -d     disgcl_linux.nn.tar.gz


b) Restore files from the tar file with the command

                  tar   xvf   disgcl_linux.nn.tar    


c) Change to the installation directory of DISGCL

                  cd    dislin_6.3

d) Choose a directory in the file structure where DISGCL should be
   installed and define the environment variable DISLIN with it:

   For example:    DISLIN=$HOME/dislin   (for sh, ksh)
                   export DISLIN

            or:    setenv DISLIN $HOME/dislin  
                                                          (for csh)  
       
e) Run the install program with the command 

                   INSTALL

   This program copies files to $DISLIN and sets protections.

f) To make DISGCL available for general use, write the following com-
   mands to your .profile

                    export DISLIN=xxx                     
                    PATH=${PATH}:${DISLIN}/bin

   where xxx is the path of the DISLIN directory.


   For a C-shell, you should include the commands

                    setenv DISLIN xxx
                    setenv PATH ${PATH}:${DISLIN}/bin

   into your .login file.
   
    
g) Check the installation by running the DISGCL examples

     Type:    disgcl  curve
       or:    disgcl  surface
       or:    disgcl  pie
       or:    disgcl  bars
       or:    disgcl  world
       or:    disgcl  contour
       or:    disgcl  conshd

   The examples can be found in the directory:  $DISLIN/gcldir

h) You can delete the installation directory 'dislin_6.3'.


3.) FTP Sites

   DISLIN and DISGCL are available via ftp anonymous from the
   following sites:

      ftp://ftp.gwdg.de/pub/grafik/dislin
      ftp://linhmi.mpae.gwdg.de/pub/dislin

   The DISLIN Home Page is:

      http://www.mpae.gwdg.de/dislin/dislin.html
