Re: [Matplotlib-users] odd "singular matrix" error

[C M <cmp...@gm...>]

Still though, I thought we had enough logic checks to prevent this sort of
>> error. I see you are using Python 2.5, which is older than what we
>> currently support. Which version of matplotlib are you using?
>>
>
> I'm using matplotlib 1.1.0. I could try upgrading.
>

Ben and others,

OK, I tried upgrading to Python 2.6 and Matplotlib 1.4.2. The problem with
the singular matrix goes away!  But...

...But now I have no patch shown on the plot. This is the function I am
using now to add a patch (editing to just keep the MPL relevant
stuff)...maybe this is no longer a good way?:

    def AddPatch(self,):
                ax = self.subplot
                verts = [
                    (start, y-scaling_value), # left, bottom
                    (start, y+scaling_value), # left, top
                    (stop, y+scaling_value), # right, top
                    (stop, y-scaling_value), # right, bottom
                    (0., 0.), # ignored
                    ]
                codes = [Path.MOVETO,
                         Path.LINETO,
                         Path.LINETO,
                         Path.LINETO,
                         Path.CLOSEPOLY,
                         ]

                x = [start, stop]              # x range of box (in data
coordinates)
                height = 12 # of box in device coords (pixels)
                path = mpath.Path([[x[0], -height], [x[1], -height],
                   [x[1], height],  [x[0], height],
                   [x[0], -height]])

                #USING THE NEW TRANSFORMS
                fixed_pt_trans = FixedPointOffsetTransform(ax.transData,
(0, y))
                xdata_yfixed =
mtrans.blended_transform_factory(ax.transData, fixed_pt_trans)

                patch = patches.PathPatch(path, transform=xdata_yfixed,
facecolor=color,alpha=0.4, lw=1, edgecolor='grey')

                ax.add_patch(patch)