[Numpy-discussion] dot documentation
Fri Aug 7 16:24:24 CDT 2009
Oh. b.shape = (2,). So I suppose the second to last dimension is, in
fact, the last dimension...and 2 == 2.
On Fri, Aug 7, 2009 at 2:19 PM, T J<email@example.com> wrote:
> 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:
> --> array([[1,2],[1,2]])
> and then the multiplication done as normal (but this would give a 2x2 result).
> Can someone explain this to me?
More information about the NumPy-Discussion