On Wed, Feb 1, 2012 at 10:57 PM, Pierre Haessig
I've no idea what's going on, but here is my $0.02 contribution. I reproduced the bug (numpy 1.5.1) with a rather minimal script. See attached.
I reproduced the issue with Pierre's script also in numpy 1.6.1 and latest github (2.0.0.dev-b8bfcd0). In newer versions the error message is: Traceback (most recent call last): File "ma_tiling_issue.py", line 18, in <module> a/100. #raises ValueError: invalid return array shape File "/usr/local/lib/python2.7/dist-packages/numpy/ma/core.py", line 3654, in __div__ return divide(self, other) File "/usr/local/lib/python2.7/dist-packages/numpy/ma/core.py", line 1078, in __call__ m |= ma ValueError: non-broadcastable output operand with shape (3,3,3) doesn't match the broadcast shape (1,3,3,3) I still don't know what's going on. Is the internal representation (shape) of the array changed by the tile instruction? I created a ticket: http://projects.scipy.org/numpy/ticket/2035