Affine problem

Hi All,

I have a problem plotting text on a graph that's been rotated using an Affine transform. I think I can demonstrate the cause of the problem with the following code snippet.

···

###
from matplotlib.transforms import Affine, Value

a = Affine(Value(1), Value(1), Value(-1), Value(1), Value(0), Value(0))

xy = (123, 456)
print a.inverse_xy_tup(a.xy_tup(xy))
###

Result is not 123, 456 as I expect but -456, 456.

I think the problem is in _transform.cpp. This patch (from HEAD revision in SVN) gives the correct result.

1704,1705c1704,1705
< _ibval = scale*_cval;
< _icval = -scale*_bval;
---
> _ibval = -scale*_bval;
> _icval = -scale*_cval;

Thanks,
Alan