Re: patch and FaceAlpha property problem

[Fredrik Lingvall]

The output  file (debug.gp) don't have any "transparent" setting anywhere. However, __go_draw_axes__.m (around line 664)
has this:

         if (mono)
           colorspec = "";
         elseif (__gnuplot_has_feature__ ("transparent_patches")
             && isscalar (obj.facealpha))
                   colorspec = sprintf ("lc rgb \"#%02x%02x%02x\" fillstyle transparent solid %f",
                      round (255*color), obj.facealpha);
         else
           colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",
                    round (255*color));
         endif

which should set the fillstyle to transparent!?

octave:66> __gnuplot_has_feature__ ("transparent_patches")
ans =  1

/Fredrik

On Thu, Feb 4, 2010 at 11:22 PM, John W. Eaton <address@hidden> wrote:

On  4-Feb-2010, Fredrik Lingvall wrote:

| Hi,
|
| I'm trying to set the FaceAlpha of patch objects using:
|
| [fc,v] = isosurface(x,y,z,pdf,levels(n));
|
| p = patch('Faces',fc,'Vertices',v);
|
| set(p,'FaceColor','blue','EdgeColor','none','FaceAlpha',0.1)
|
| But setting FaceAlpha to 0.1 don't have any effect. I'm I doing something
| wrong here?
|
| I'm using:
|
| octave --version
| GNU Octave, version 3.2.3
| Copyright (C) 2009 John W. Eaton and others.
| This is free software; see the source code for copying conditions.
| There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
| FITNESS FOR A PARTICULAR PURPOSE.
|
| Octave was configured for "x86_64-unknown-linux-gnu".
|
| with a resent gnuplot cvs version.

After you have your plot created, you can execute

 drawnow ("x11", "/dev/null", 0, "debug.gp")

to dump the commands that Octave sends to gnuplot to the file
debug.gp.  Does that file contain the right magic for the feature you
want?  If not, someone needs to fix the __go_draw_axes__ function to
implement the feature.

jwe