-dpng gives "invalid command"

[Thomas Treichl]

John B. Thoo schrieb:
> Hi, Thomas.
> 
> gnuplot> show version long
> 
>         G N U P L O T
>         Version 4.2 patchlevel 5
>         last modified Mar 2009
>         System: Darwin 8.11.0
> 
>         Copyright (C) 1986 - 1993, 1998, 2004, 2007 - 2009
>         Thomas Williams, Colin Kelley and many others
> 
>         Type `help` to access the on-line reference manual.
>         The gnuplot FAQ is available from http://www.gnuplot.info/faq/
> 
>         Send bug reports and suggestions to 
> <http://sourceforge.net/projects/gnuplot>
> 
> Compile options:
> +READLINE  -LIBREADLINE  +HISTORY  +BACKWARDS_COMPATIBILITY  +BINARY_DATA
> -LIBGD
> -NOCWDRC  +X11  +X11_POLYGON  +MULTIBYTE  +USE_MOUSE  +HIDDEN3D_QUADTREE
> +DATASTRINGS  +HISTOGRAMS  +OBJECTS  +STRINGVARS  +MACROS  +IMAGE
> 
> DRIVER_DIR     = "/usr/local/libexec/gnuplot/4.2"
> GNUPLOT_PS_DIR = "/usr/local/share/gnuplot/4.2/PostScript"
> HELPFILE       = "/usr/local/share/gnuplot/4.2/gnuplot.gih"
> 
> gnuplot>
> 
> 
> Thanks.
> 
> ---John.

Then yes, you're right - you're missing support for *png. Your version of 
Gnuplot has not been compiled against libgd. libgd (and libpng and libjpg...) is 
the library that you need to create graphics in *png, *jpg and *gif.

As your binary is in /usr/local I would expect you either compile and install 
Gnuplot for yourself or you use MacPorts? Either or, you need a binary that 
should give you something like this to save in *png on your Mac (compare compile 
options GD_* from my machine with yours):

   gnuplot> show version long

         G N U P L O T
         Version 4.2 patchlevel 5
         last modified Mar 2009
         System: Darwin 8.11.1

         Copyright (C) 1986 - 1993, 1998, 2004, 2007 - 2009
         Thomas Williams, Colin Kelley and many others

         Type `help` to access the on-line reference manual.
         The gnuplot FAQ is available from http://www.gnuplot.info/faq/

         Send bug reports and suggestions to
   <http://sourceforge.net/projects/gnuplot>

   Compile options:
   -READLINE  +LIBREADLINE  +HISTORY  +BACKWARDS_COMPATIBILITY  +BINARY_DATA
   +GD_PNG  +GD_JPEG  +GD_GIF  +ANIMATION
   -NOCWDRC  +X11  +X11_POLYGON  +MULTIBYTE  +USE_MOUSE  +HIDDEN3D_QUADTREE
   +DATASTRINGS  +HISTOGRAMS  +OBJECTS  +STRINGVARS  +MACROS  +IMAGE

   DRIVER_DIR     =
"/Users/Thomas/bin/Octave.app.3.2.0/Gnuplot.app/Contents/Resources/libexec/gnuplot/4.2"
   GNUPLOT_PS_DIR = "/tmp/gnuplot-i386/share/gnuplot/4.2/PostScript"
   HELPFILE       = 
"/Users/Thomas/bin/Octave.app.3.2.0/Gnuplot.app/Contents/Resources/share/gnuplot/4.2/gnuplot.gih"

Hope this helps somehow,

   Thomas