[Numpy-discussion] dot documentation
Fri Aug 7 16:19:16 CDT 2009
Hi, the documentation for dot says that a value error is raised if:
If the last dimension of a is not the same size as the
second-to-last dimension of b.
This doesn't appear to be the case:
>>> a = array([[1,2],[3,4]])
>>> b = array([1,2])
I can see *how* 5,11 is obtained, but it seems this should have raised
a ValueError since the 2 != 1. So the actual code must do something
more involved. When I think about broadcasting, it seems that maybe b
should have been broadcasted to:
and then the multiplication done as normal (but this would give a 2x2 result).
Can someone explain this to me?
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