[Numpy-discussion] matrix indexing question
Colin J. Williams
cjw@sympatico...
Mon Mar 26 11:05:18 CDT 2007
Alan G Isaac wrote:
> On Mon, 26 Mar 2007, "Colin J. Williams" apparently wrote:
>> Perhaps things would be clearer if we thought of the
>> constituent groups of data in a matrix as being themselves
>> matrices.
>
> This "thinking of" is what you have suggested before.
> You need to explain why it is not begging the question.
>
> Cheers,
> Alan Isaac
Perhaps it would now help if you redefined the question.
In an earlier posting, you appeared anxious that the matrix and the
array behave in the same way. Since they are different animals, I see
sameness of behaviour as being lower on the list of desirables than
fitting the standard ideas of matrix algebra.
Suppose that a is a row vector, b a column vector and A a conforming
matrix then:
a * A
A * b
and b.T * A are all acceptable operations.
One would expect the iteration over A to return row vectors, represented
by (1, n) matrices.
Colin W.
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