NAME

       gdl - GNU Data Language incremental compiler

SYNOPSIS

       gdl [--help] [-h] [--version] [-v] [-V] [[-]-quiet] [-q] [ -arg value ] [ -args ...  ] [ -e statement ] [
       -pref=/path/to/preferenceFile ] [ batch_file ...  ]

DESCRIPTION

       gdl  is  an incremental compiler for the GNU Data Language (GDL).  GDL is being developed with the aim of
       providing an open-source drop-in replacement for ITTVIS Interactive  Data  Language  (IDL).  It  is  also
       partially  compatible  with  Visual  Numerics  (VN) PV-WAVE. IDL and PV-WAVE are registered trademarks of
       ITTVIS and VN, respectively.  GDL and its library routines are designed as  a  tool  for  numerical  data
       analysis  and  visualisation.   GDL  is dynamically typed, vectorized and has object-oriented programming
       capabilities.  The library routines  handle  numerical  calculations,  data  visualisation,  signal/image
       processing, file input/output (incl. graphical and scientific data formats such as TIFF, PNG, netCDF, HDF
       etc) and interaction with host OS.

       Information on GDL/IDL/PV-WAVE syntax and library routines can be found in e.g.:

       - GDL documentation draft at: http://gnudatalanguage.sf.net/gdl.pdf

       - IDL manual on-line @ NASA.gov: http://idlastro.gsfc.nasa.gov/idl_html_help/home.html

       - ITTVIS (ittvis.com) and Visual Numerics (vni.com) websites

       - comp.lang.idl-pvwave newsgroup

       A vast part of GDL library routines is implemented using open-source libraries including GSL, plPlot, and
       optionally: readline, FFTW, ImageMagick, netCDF, HDF4, HDF5, libproj4, UDUNITS-2, libps and others.

OPTIONS

       --help (or -h)
              Show summary of options

       --version (or -v, -V)
              Show version of program

       --quiet (or -quiet, -q)
              Suppress welcome messages

       -arg value
              Tells COMMAND_LINE_ARGS() to report the following argument (may be specified more than once)

       -args ...
              Tells COMMAND_LINE_ARGS() to report all following arguments

       -e statement
              Execute  given  statement and exit (last occurance taken into account only, executed after startup
              file, may not be specified together with batch files)

       -pref=/path/to/PreferenceFile
              (only partially working now) setting using external text  file  few  variables  including  default
              preferences (e.g. X11 Windows Size)

       The -demo, -em, -novm, -queue, -rt, -ulicense and -vm options
              are ignored for compatibility with IDL.

       A list of batch files to be executed before entering the interactive
              mode (but after executing a startup file, if specified) may be given when not using the -e option.

FILES

       $DATADIR/gnudatalanguage/lib/*.pro
              Library  routines  implemented  in  GDL.  $DATADIR  is  specified  during  compilation and usually
              translates to /usr/share, /usr/local/share or alike. GDL includes this  directory  in  its  search
              path unless GDL_PATH or IDL_PATH env. variables are set (see below).

       $HOME/.gdl/history
              A file used for storing the history of commands issued in the interactive mode

ENVIRONMENT

       The  following  environment  variables have special meaning to gdl.  The GDL_* variant, if defined, takes
       precedence over any corresponding IDL_* variant.

       GDL_PATH, IDL_PATH
              The GDL command (script) search path.

       GDL_STARTUP, IDL_STARTUP
              A file of commands to be executed on startup.

       GDL_TMPDIR, IDL_TMPDIR
              A directory in which temporary files may be created.

       HOME, SHELL
              Variables influencing shell invocations from within GDL (SPAWN procedure  and  the  $  interpreter
              command).  Value of HOME determines as well the location of the GDL history-file.

       PATH   Determines  search  path when spawning child processes using the SPAWN procedure with the /NOSHELL
              keyword set.

       PYTHONPATH
              Influences behaviour of PYTHON procedure and PYTHON() function (available if GDL is compiled  with
              support for calling Python code)

       GDL_MPI
              A message to be sent out using MPI_Send before initialization of the interpreter (available if GDL
              is compiled with support for MPI)

       DISPLAY, XENVIRONMENT
              Tell GDL how to connect to the X server

       PLPLOT_DRV_DIR
              Override the default location of PLplot dynamic drivers.

       LC_*   The locale-related settings accessible via LOCALE_GET() (GDL always uses the C locale internally)

BUGS

       Please report bugs, comments, patches or feature requests at http://sf.net/projects/gnudatalanguage/

AUTHOR

       The  primary author of GDL is Marc Schellens <m_schellens@users.sourceforge.net>.  A list of contributors
       is available in the AUTHORS file shipped with GDL, and on the project website (see above).

       The original version of this manual page was written by Sergio Gelato <Sergio.Gelato@astro.su.se>.  It is
       currently a part of the GDL package, and is maintained by the GDL Team.

SEE ALSO

       netcdf(3), hdf(1), gsl(3)

The GDL Team                                       2012-11-21                                             GDL(1)