[Matplotlib-users] positioning an inset_axes precisely in the figure

[per f. <per...@gm...>]

hi all,

i am using mpl_toolkits.axes_grid.inset_locator.inset_axes to plot an
inset axes inside my figure, as follows:

  inset = inset_axes(s,
		       width="30%", # width = 30% of parent_bbox
		       height=.5, # height : 1 inch
                       loc=4
)

i am trying to use the bbox_transform keyword argument to reposition
this within the figure -- i want to use figure coordinates rather than
the loc= keyword.

if i try the following:

    inset = inset_axes(s,
		       width="30%", # width = 30% of parent_bbox
		       height=.5, # height : 1 inch
		       bbox_transform=(0.1, 0.1))

then i get the error:

  File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/offsetbox.py",
line 910, in get_bbox_to_anchor
    transform)
  File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/transforms.py",
line 974, in __init__
    assert isinstance(transform, Transform)
AssertionError

any idea how i can reposition the inset axes? thanks very much for your help.