Re: plplot octave

[Orion Poplawski]

John W. Eaton wrote:
> On 23-Sep-2007, address@hidden wrote:
> | Later versions also break the plplot octave interface which is shipped in
> | the current Fedora 7 release.  If anyone can offer some help to that
> | project to get the plotting code working with the latest octave, that
> | would be greatly appreciated.
>
> Filing a bug report for what breaks would be a good first step.

Well, the problem is not particularly obvious to me, having no knowledge 
of octave's plotting internals.

First issue seems to be getting into an infinite recursion loop calling 
the plplot version of "figure".  This call "hold off", which calls 
"/usr/share/octave/2.9.14/m/plot/__plt_get_axis_arg__.m", which calls 
/usr/share/octave/2.9.14/m/plot/gca.m which calls 
/usr/share/octave/2.9.14/m/plot/gcf.m which calls figure again.

Looks like it tries to save the current hold state, turn it off, then 
restore the hold state.  Not sure what this really does or if it's 
needed still.

There are other calls to hold/ishold scattered around too that lead to 
these failures as well as a failure in gca with get(gcf(), "something") 
failing.

figure does:

  global __pl __tk_name

so that's whet __pl refers to below.

Next seems to be that __pl.lab_str has changed in some way.  The 
following fails:


      if (!struct_contains(__pl, "lab_str"))
        __pl.lab_str(strm) = "";        # label string
      endif

with:

error: A(idx) = []: index out of range
error: assignment to structure element failed
error: assignment failed, or no method for `struct = string'
error: evaluating assignment expression near line 176, column 21

Also, __pl.open seems to have gone away.  plplot code seems to have 
tried to use this to keep track of various figure states.


--
Orion Poplawski
Technical Manager                     303-415-9701 x222
NWRA/CoRA Division                    FAX: 303-415-9702
3380 Mitchell Lane                  address@hidden
Boulder, CO 80301              http://www.cora.nwra.com