Re: How do I use octave gnuplot to html5 canvas terminal?

[Ben Abbott]

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On Jan 19, 2012, at 5:37 PM, Paul Perry wrote:

> On Thu, Jan 19, 2012 at 3:39 PM, Ben Abbott <address@hidden> wrote:
> 
> On Jan 19, 2012, at 2:40 PM, Paul Perry wrote:
> 
> > On Thu, Jan 19, 2012 at 9:47 AM, Ben Abbott <address@hidden> wrote:
> >
> > On Jan 19, 2012, at 6:48 AM, Paul Perry wrote:
> >
> > > I am on a Mac OS X 10.6.8 Octave 3.4 and I would like to output a plot to 
> > > an html5 canvas? How do I send a command to gnuplot to set the terminal 
> > > to canvas?  Is this supported?
> >
> > Octave doesn't yet include support for gnuplot's html5 terminal.
> >
> > I'll need to look at the appropriate gnuplot docs to include it. Can you 
> > tell me which version of gnuplot has this terminal ?
> >
> > If you're interested in trying to modify Octave to enable the htlm5 
> > terminal, the sources to patch are ...
> >
> >        __gnuplot_drawnow__.m: gnuplot_set_term()
> >        __gnuplot_drawnow__.m: gnuplot_is_enhanced_term()
> >
> > Once html5 is added there, you can produce a plot with ...
> >
> >        plot (rand (3))
> >        drawnow ("html5", "plot.html5", false, "/dev/null")
> >
> > I've been considering modifying __gnuplot_drawnow__.m to support gnuplot 
> > terminals that are not explicitly supported by Octave. Perhaps this is an 
> > opportunity to me to do that.
> >
> > To add html5 support the print(), then the sources to modify include ...
> >
> >        print.m
> >        __gnuplot_print__.m
> >
> > Ben
> >
> 
> > Gnuplot 4.4 seems to have this terminal.  In the documentation ( 
> > http://www.gnuplot.info/docs_4.4/gnuplot.pdf ) section 83.7 (pp. 189) they 
> > describe the following commands:
> >
> > set term canvas name 'fishplot'
> > set output 'fishplot.js'
> >
> > I installed a gnuplot-4.4.3-aqua-i386.dmg for Octave 3.4.  Starting just 
> > Gnuplot and typing "set terminal canvas" worked.  plot(rand(3)) resulted in 
> > an html output.  So it looks like I'm close!
> >
> > I'd have to figure out how to modify the Octave files you list.
> >
> > Thanks.
> >
> > p.s. Here are some demos: http://gnuplot.sourceforge.net/demo_canvas/
> >
> > How do I find which version of gnuplot I installed with Octave 3.4
> 
> *** Please don't top-post. By replying below those who arrive late can follow 
> along. Thanks ***
> 
> Ok. Thanks. I was looking for a terminal named "html5". I didn't realize it 
> was called canvas. My gnuplot is 4.4.4 so I should be able to add this 
> terminal.
> 
> I've added a feature request to the bug tracker.
> 
>        https://savannah.gnu.org/bugs/index.php?35332
> 
> To see which gnuplot your Octave is using ...
> 
>        cd (fileparts (which ("plot")))
>        __gnuplot_version__
>        ans = 4.4.4
> 
> I just tried the commands below
> 
>        peaks ()
>        drawnow ("canvas", "peaks.html", false, "debug.gp")
> 
> This does render an html5 document. But the plot appears to be rendered in 
> pixels, not inches.
> 
> I made the follow change to debug.gp
> 
> $ diff -ua debug.orig.gp debug.gp
> --- debug.orig.gp       2012-01-19 15:08:10.000000000 -0500
> +++ debug.gp    2012-01-19 15:08:21.000000000 -0500
> @@ -1,5 +1,5 @@
>  unset multiplot;
> -set terminal canvas enhanced size 7.77777777778,5.83333333333
> +set terminal canvas enhanced size 640,480
>  set output 'myplot.html';
>  set multiplot;
> 
> Then from a bash command line, I run the new version through gnuplot.
> 
>        gnuplot debug.gp
> 
> The result rendered as expected in web browser.
> 
> Ben
> 
> Thank you, I got it to work, with some girations.  
> I checked my gnuplot version and I have version 4.4.3 .  
> I ran the drawnow command as you specified, modified the output debug.gp file 
> with the new terminal size (640,480), but the page was simply white.  
> Looking at the HTML I saw references to:
> 
> <script src="/tmp/gnuplot-i386/share/gnuplot/4.4/js/canvastext.js"></script>
> <script 
> src="/tmp/gnuplot-i386/share/gnuplot/4.4/js/gnuplot_common.js"></script>
> <link type="text/css" 
> href="/tmp/gnuplot-i386/share/gnuplot/4.4/js/gnuplot_mouse.css" 
> rel="stylesheet">
> 
> but these files don't exist in these locations, but on my mac install I found 
> them here: 
> /Applications/Gnuplot.app/Contents/Resources/share/gnuplot/4.4
> 
> after changing the src references it worked.  
> 
> Thank you!  Paul

Turns out the fix was simple. I had already added support for the canvas 
terminal but hadn't realized its units were pixels, not inches.  If you like 
you can follow the link below and transplant the change into your Octave.

        http://hg.savannah.gnu.org/hgweb/octave/rev/921b15c13adc

Ben