NAME

SYNOPSIS

DESCRIPTION

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

- GDL documentation draft at: http://aramis.obspm.fr/~coulais/GDL/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

- newsletter at: https://sympa.obspm.fr/wws/info/gdl-announces

A vast part of GDL library routines is implemented using open-source libraries including GSL, plPlot, and optionally: readline, FFTW, Eigen3, ImageMagick, netCDF, HDF4, HDF5, PROJ, 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 occurrence 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)

--fakerelease version

setting !VERSION.RELASE to that value. !VERSION.RELASE is often tested by procedures to decide whether some function or option should be used. It is sometimes possible to use this option to fool a procedure that request a specific value of !VERSION.RELEASE (e.g. atv.pro)

--fussy

signals that all used procedures will adhere with modern IDL, where "()" are for functions and "[]" are for arrays. This speeds up (sometimes terribly) compilation but choke on every use of "()" with arrays. Conversion of procedures to modern IDL can be done with D. Landsman's idlv4_to_v5 procedure. Use enviromnment variable "GDL_IS_FUSSY" to set up permanently this feature.

Incidentally "being fussy" can help find all places in a procedure that need to be corrected to have it in the modern IDL format.

--sloppy

inverse of fussy above. Sets the traditional (default) compiling option where "()" can be used both with functions and arrays. Needed to counteract temporarily the effect of the enviromnment variable "GDL_IS_FUSSY".

--use-wx

Tells GDL to use WxWidgets graphics instead of X11 or Windows. (nicer plots). Also enabled by setting the environment variable GDL_USE_WX to a non-null value.

--no-use-wx

Tells GDL no to use WxWidgets graphics, even if env. var. "GDL_USE_WX" is set.

--no-dSFMT

Tells GDL not to use double precision SIMD oriented Fast Mersenne Twister(dSFMT) for random values. Also disabled by setting the environment variable GDL_NO_DSFMT to a non-null value.

With dSFMT, although the Mersenne Twister algorithm is the same as in modern IDL, the values are computed in parallel (hence a speed gain) but the output order is not the same as IDL. Also, the seed is different. Theses differences should not be a problem as it is discouraged to interfere with seed values.

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 (if GDL compiled within ReadLine)

ENVIRONMENT

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)

GDL_GR_WIN_HEIGHT

Sets the preference for the default height of a Windows(tm) graphic window

GDL_GR_WIN_QSCREEN

if set to true (1) this will prevent the use of the GDL_GR_WIN_HEIGHT and GDL_GR_WIN_WIDTH preferences and the default dimensions of graphic windows will be 1/4 of the screen dimensions

GDL_GR_WIN_WIDTH

Sets the preference for the default width of a Windows(tm) graphic window

GDL_GR_X_HEIGHT

Sets the preference for the default height of an X11 graphic window

GDL_GR_X_QSCREEN

if set to true (1) this will prevent the use of the GDL_GR_X_HEIGHT and GDL_GR_X_WIDTH preferences and the default dimensions of graphic windows will be 1/4 of the screen dimensions

GDL_GR_X_WIDTH

Sets the preference for the default width of an X11 graphic window

GDL_WX_BACKEND

can be set to [0,1,2] which will select, respectively, the backends 0,1 or 2 of plplot's old wxWidgets driver (plplot versions < 5.10). Backend 2 has antialiasing enabled.

GDL_MAPS_DIR

If not automatically found, tells GDL where the maps files (coasts rivers, etc, used by MAPS_CONTINENTS) are located. These are in Shapefile format and newer versions can possibly be present on naturalearthdata.com

BUGS

AUTHOR

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