1GDL(1)                      General Commands Manual                     GDL(1)
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NAME

6       gdl - GNU Data Language incremental compiler
7

SYNOPSIS

9       gdl [--help] [-h] [--version] [-v] [-V] [[-]-quiet] [-q] [ -arg value ]
10       [ -args ...  ] [ -e statement ]  [  -pref=/path/to/preferenceFile  ]  [
11       batch_file ...  ]
12

DESCRIPTION

14       gdl is an incremental compiler for the GNU Data Language (GDL).  GDL is
15       being developed with the aim of providing an  open-source  drop-in  re‐
16       placement for Interactive Data Language (IDL) (RSI then ITTVIS then Ex‐
17       elis and now Harris Geospatial Solutions, Inc.). It is  also  partially
18       compatible  with Visual Numerics (VN) PV-WAVE. IDL and PV-WAVE are reg‐
19       istered trademarks of L3Harris and VN, respectively.  GDL and  its  li‐
20       brary  routines  are designed as a tool for numerical data analysis and
21       visualisation.  GDL  is  dynamically  typed,  vectorized  and  has  ob‐
22       ject-oriented  programming  capabilities.   The library routines handle
23       numerical calculations, data  visualisation,  signal/image  processing,
24       file  input/output (incl. graphical and scientific data formats such as
25       TIFF, PNG, netCDF, HDF etc) and interaction with host OS.
26
27       Information on GDL/IDL/PV-WAVE syntax and library routines can be found
28       in e.g.:
29
30       -      GDL      documentation      draft      at:     http://aramis.ob
31       spm.fr/~coulais/GDL/gdl.pdf
32
33       -     IDL     manual     on-line     @     NASA.gov:      http://idlas
34       tro.gsfc.nasa.gov/idl_html_help/home.html
35
36       - ITTVIS (ittvis.com) and Visual Numerics (vni.com) websites
37
38       - comp.lang.idl-pvwave newsgroup
39
40       - newsletter at: https://sympa.obspm.fr/wws/info/gdl-announces
41
42       A  vast  part  of GDL library routines is implemented using open-source
43       libraries  including  GSL,  plPlot,  and  optionally:  readline,  FFTW,
44       Eigen3, ImageMagick, netCDF, HDF4, HDF5, libproj4, UDUNITS-2, libps and
45       others.
46

OPTIONS

48       --help (or -h)
49              Show summary of options
50
51       --version (or -v, -V)
52              Show version of program
53
54       --quiet (or -quiet, -q)
55              Suppress welcome messages
56
57       -arg value
58              Tells COMMAND_LINE_ARGS() to report the following argument  (may
59              be specified more than once)
60
61       -args ...
62              Tells COMMAND_LINE_ARGS() to report all following arguments
63
64       -e statement
65              Execute given statement and exit (last occurrence taken into ac‐
66              count only, executed after startup file, may  not  be  specified
67              together with batch files)
68
69       -pref=/path/to/PreferenceFile
70              (only  partially  working  now) setting using external text file
71              few variables including default preferences  (e.g.  X11  Windows
72              Size)
73
74       --fakerelease version
75              setting  !VERSION.RELASE to that value. !VERSION.RELASE is often
76              tested by procedures to decide whether some function  or  option
77              should  be  used. It is sometimes possible to use this option to
78              fool a procedure that request a specific value  of  !VERSION.RE‐
79              LEASE (e.g. atv.pro)
80
81       --fussy
82              signals  that  all  used procedures will adhere with modern IDL,
83              where "()" are for functions and  "[]"  are  for  arrays.   This
84              speeds  up  (sometimes  terribly) compilation but choke on every
85              use of "()" with arrays.  Conversion of procedures to modern IDL
86              can be done with D. Landsman's idlv4_to_v5 procedure.  Use envi‐
87              romnment variable "GDL_IS_FUSSY" to set up permanently this fea‐
88              ture.
89
90              Incidentally  "being fussy" can help find all places in a proce‐
91              dure that need to be corrected to have it in the modern IDL for‐
92              mat.
93
94       --sloppy
95              inverse  of fussy above.  Sets the traditional (default) compil‐
96              ing option where "()"  can be used both with functions  and  ar‐
97              rays.   Needed to counteract temporarily the effect of the envi‐
98              romnment variable "GDL_IS_FUSSY".
99
100       --use-wx
101              Tells GDL to use WxWidgets graphics instead of X11  or  Windows.
102              (nicer plots).  Also enabled by setting the environment variable
103              GDL_USE_WX to a non-null value.
104
105       --no-use-wx
106              Tells GDL no to  use  WxWidgets  graphics,  even  if  env.  var.
107              "GDL_USE_WX" is set.
108
109       --no-dSFMT
110              Tells  GDL  not  to  use  double  precision  SIMD  oriented Fast
111              Mersenne Twister(dSFMT) for random  values.   Also  disabled  by
112              setting  the  environment  variable  GDL_NO_DSFMT  to a non-null
113              value.
114
115              With dSFMT, although the Mersenne Twister algorithm is the  same
116              as  in  modern IDL, the values are computed in parallel (hence a
117              speed gain) but the output order is not the same as  IDL.  Also,
118              the seed is different.  Theses differences should not be a prob‐
119              lem as it is discouraged to interfere with seed values.
120
121
122              The -demo, -em, -novm, -queue, -rt, -ulicense  and  -vm  options
123              are ignored for compatibility with IDL.
124
125       A list of batch files to be executed before entering the interactive
126              mode  (but  after executing a startup file, if specified) may be
127              given when not using the -e option.
128

FILES

130       $DATADIR/gnudatalanguage/lib/*.pro
131              Library routines implemented in GDL. $DATADIR is specified  dur‐
132              ing  compilation  and usually translates to /usr/share, /usr/lo‐
133              cal/share or alike. GDL includes this directory  in  its  search
134              path unless GDL_PATH or IDL_PATH env. variables are set (see be‐
135              low).
136
137       $HOME/.gdl/history
138              A file used for storing the history of commands  issued  in  the
139              interactive mode (if GDL compiled within ReadLine)
140

ENVIRONMENT

142       The  following  environment variables have special meaning to gdl.  The
143       GDL_* variant, if defined,  takes  precedence  over  any  corresponding
144       IDL_* variant.
145
146       GDL_PATH, IDL_PATH
147              The GDL command (script) search path.
148
149       GDL_STARTUP, IDL_STARTUP
150              A file of commands to be executed on startup.
151
152       GDL_TMPDIR, IDL_TMPDIR
153              A directory in which temporary files may be created.
154
155       HOME, SHELL
156              Variables  influencing  shell invocations from within GDL (SPAWN
157              procedure and the $ interpreter command).  Value of HOME  deter‐
158              mines as well the location of the GDL history-file.
159
160       PATH   Determines  search  path when spawning child processes using the
161              SPAWN procedure with the /NOSHELL keyword set.
162
163       PYTHONPATH
164              Influences behaviour of PYTHON procedure and  PYTHON()  function
165              (available  if  GDL  is compiled with support for calling Python
166              code)
167
168       GDL_MPI
169              A message to be sent out using MPI_Send before initialization of
170              the  interpreter  (available if GDL is compiled with support for
171              MPI)
172
173       DISPLAY, XENVIRONMENT
174              Tell GDL how to connect to the X server
175
176       PLPLOT_DRV_DIR
177              Override the default location of PLplot dynamic drivers.
178
179       LC_*   The locale-related settings accessible via LOCALE_GET() (GDL al‐
180              ways uses the C locale internally)
181
182       GDL_GR_WIN_HEIGHT
183              Sets  the  preference  for  the  default height of a Windows(tm)
184              graphic window
185
186       GDL_GR_WIN_QSCREEN
187              if  set  to  true  (1)  this  will  prevent  the  use   of   the
188              GDL_GR_WIN_HEIGHT  and  GDL_GR_WIN_WIDTH preferences and the de‐
189              fault dimensions of graphic windows will be 1/4  of  the  screen
190              dimensions
191
192       GDL_GR_WIN_WIDTH
193              Sets  the  preference  for  the  default  width of a Windows(tm)
194              graphic window
195
196       GDL_GR_X_HEIGHT
197              Sets the preference for the default height  of  an  X11  graphic
198              window
199
200       GDL_GR_X_QSCREEN
201              if   set   to  true  (1)  this  will  prevent  the  use  of  the
202              GDL_GR_X_HEIGHT and GDL_GR_X_WIDTH preferences and  the  default
203              dimensions  of  graphic windows will be 1/4 of the screen dimen‐
204              sions
205
206       GDL_GR_X_WIDTH
207              Sets the preference for the default width of an X11 graphic win‐
208              dow
209
210       GDL_WX_BACKEND
211              can be set to [0,1,2] which will select, respectively, the back‐
212              ends 0,1 or 2 of plplot's old wxWidgets driver (plplot  versions
213              < 5.10). Backend 2 has antialiasing enabled.
214
215       GDL_MAPS_DIR
216              If  not  automatically  found,  tells  GDL  where the maps files
217              (coasts rivers,  etc,  used  by  MAPS_CONTINENTS)  are  located.
218              These are in Shapefile format and newer versions can possibly be
219              present on naturalearthdata.com
220

BUGS

222       Please  report  bugs,  comments,  patches  or   feature   requests   at
223       https://github.com/gnudatalanguage/gdl/
224

AUTHOR

226       The  primary author of GDL is Marc Schellens <m_schellens@users.source‐
227       forge.net>.  A list of contributors is available in  the  AUTHORS  file
228       shipped with GDL, and on the project website (see above).
229
230       The  original  version of this manual page was written by Sergio Gelato
231       <Sergio.Gelato@astro.su.se>.  It is currently a part of the  GDL  pack‐
232       age, and is maintained by the GDL Team.
233

SEE ALSO

235       netcdf(3), hdf(1), gsl(3), eigen3, plplot, fftw
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237
238
239The GDL Team                      2020-05-19                            GDL(1)
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