Re: -dpng gives "invalid command"

[John B. Thoo]

On Jul 10, 2009, at 10:56 AM, Ben Abbott wrote:

> On Friday, July 10, 2009, at 12:37PM, "John B. Thoo"  
> <address@hidden> wrote:
> > Hi, everyone.
> >
> > I can save a plot to EPS by
> >
> >   print ("foo.eps", "-deps")
> >
> > but when I try to save a plot to PNG by
> >
> >   print ("foo.png", "-dpng")
> >
> > I get a run of errors like
> >
> >
> > gnuplot> e
> >          ^
> >          line 0: invalid command
> >
> >
> > and no plot is saved.
> >
> > What am I doing wrongly?
> >
> > I'm using Octave 3.0.5 and gnuplot 4.2 patchlevel 5 in an X11 xterm
> > window in Mac OS X 10.4.11.
> >
> > Thanks.
>
> I have no problem producing png output with 3.2 and gnuplot 4.2.5.
>
> Can you run gnuplot and try ...
>
>     set term png
>     set output foo.png
>     plot sin(x)
>     quit
>
> Do you still get the error?

Hi, Ben.  When I open gnuplot separately from Octave and try to "set  
term png", I get this error:


[533] bash-2.05b$ gnuplot

        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>


Terminal type set to 'aqua'
gnuplot> set term png
                  ^
         unknown or ambiguous terminal type; type just 'set  
terminal' for a list

gnuplot>


When I type just "set terminal" for a list of available terminals  
types, I get:

Available terminal types:
           aed512  AED 512 Terminal
           aed767  AED 767 Terminal
             aifm  Adobe Illustrator 3.0 Format
             aqua  Interface to graphics terminal server for Mac OS X
         bitgraph  BBN Bitgraph Terminal
              cgm  Computer Graphics Metafile
            corel  EPS format for CorelDRAW
             dumb  ascii art for anything that prints text
              dxf  dxf-file for AutoCad (default size 120x80)
            eepic  EEPIC -- extended LaTeX picture environment
              emf  Enhanced Metafile format
            emtex  LaTeX picture environment with emTeX specials
         epslatex  LaTeX picture environment using graphicx package
     epson_180dpi  Epson LQ-style 180-dot per inch (24 pin) printers
      epson_60dpi  Epson-style 60-dot per inch printers
      epson_lx800  Epson LX-800, Star NL-10, NX-1000, PROPRINTER ...
              fig  FIG graphics language for XFIG graphics editor
             gpic  GPIC -- Produce graphs in groff using the gpic  
preprocessor
          hp2623A  HP2623A and maybe others
           hp2648  HP2648 and HP2647
           hp500c  HP DeskJet 500c, [75 100 150 300] [rle tiff]
             hpdj  HP DeskJet 500, [75 100 150 300]
             hpgl  HP7475 and relatives [number of pens] [eject]
           hpljii  HP Laserjet series II, [75 100 150 300]
             hppj  HP PaintJet and HP3630 [FNT5X9 FNT9X17 FNT13X25]
           imagen  Imagen laser printer
       kc_tek40xx  MS-DOS Kermit Tek4010 terminal emulator - color
       km_tek40xx  MS-DOS Kermit Tek4010 terminal emulator - monochrome
            latex  LaTeX picture environment
               mf  Metafont plotting standard
              mif  Frame maker MIF 3.00 format
               mp  MetaPost plotting standard
          nec_cp6  NEC printer CP6, Epson LQ-800 [monocrome color  
draft]
          okidata  OKIDATA 320/321 Standard
              pbm  Portable bitmap [small medium large] [monochrome  
gray color]
             pcl5  HP Designjet 750C, HP Laserjet III/IV, etc. (many  
options)
       postscript  PostScript graphics, including EPSF embedded  
files (*.eps)
          pslatex  LaTeX picture environment with PostScript \specials
            pstex  plain TeX with PostScript \specials
         pstricks  LaTeX picture environment with PSTricks macros
              qms  QMS/QUIC Laser printer (also Talaris 1200 and  
others)
            regis  REGIS graphics language
          selanar  Selanar
            starc  Star Color Printer
              svg  W3C Scalable Vector Graphics driver
      tandy_60dpi  Tandy DMP-130 series 60-dot per inch graphics
          tek40xx  Tektronix 4010 and others; most TEK emulators
          tek410x  Tektronix 4106, 4107, 4109 and 420X terminals
          texdraw  LaTeX texdraw environment
             tgif  TGIF X11 [mode] [x,y] [dashed] ["font" [fontsize]]
         tkcanvas  Tk/Tcl canvas widget [perltk] [interactive]
             tpic  TPIC -- LaTeX picture environment with tpic  
\specials
          unknown  Unknown terminal type - not a plotting device
            vttek  VT-like tek40xx terminal emulator
              x11  X11 Window System
             xlib  X11 Window System (gnulib_x11 dump)
(END)


so I see that png is not on the list.  (No "gif" either.)  Hmm ... I  
guess that explains it.   What do you suggest I do?

Thanks.

---John.