The excellent transformations tutorial
explained exactly what I needed to do to include inserts in my figures.
Furthermore, it suggested to me that I should be able to do without
some very ugly code I had written to convert the bounding box for a
new axis instance from Axes coordinates to Figure coordinates, by
ax2 = fig.add_axes([l_axes,b_axes,width_axes,height_axes],transform=ax.transAxes)
However, this doesn't seem to work.
The workaround, suggested by Jae-Joon Lee earlier this year --
Bbox = matplotlib.transforms.Bbox.from_bounds(l_axes,b_axes,width_axes,height_axes)
trans = ax.transAxes + fig.transFigure.inverted()
l, b, w, h = matplotlib.transforms.TransformedBbox(Bbox, trans).bounds
ax2 = fig.add_axes([l, b, w, h])
is far more elegant than my original code, but it seems a pity that
fig.add_axes can't accept the transform directly.
Regards, George Nurser.