[Numpy-discussion] Release of NumPy
Alan G Isaac
aisaac at american.edu
Wed Apr 16 02:08:34 EDT 2008
> On 15/04/2008, Alan G Isaac <aisaac at american.edu> wrote:
>> I thought the context of the discussion had become something
>> like this: there is no reason for the matrix interface to
>> deviate from the array interface except as needed to provide
>> specific desired functionality. Essentially,
>> - matrix multiplication
>> - powers of square matrices
>> - submatrix creation
>> The proposal on the table is to remove an unneeded (and
>> unwanted) deviation of the matrix API from the ndarray API.
>> That is all.
On Tue, 15 Apr 2008, Stéfan van der Walt apparently wrote:
> Unless my memory fails me (again), this would result in
> another deviation from numpy: that x[0] no longer returns
> the first row of any 2D array (matrix), especially when
> dealing with matrices of shape of (1,N).
Either I do not understand you, or this is not correct, or...
Anyway, for matrix x,
x[0] should be the same as the current x.A[0]
> The whole issue occurs because a Matrix is not a proper
> container.
Right. And *that* is the case because of the attempt to
treat matrices as containers of matrices instead of as
containers of 1d arrays.
I can see no real advantage to having matrices be containers
of row vectors instead. A row vector would just be a matrix
(i.e., essentially 2d) that allowed 1d style indexing.
Again I ask, have you ever needed such a thing?
> My favorite quote in these threads so far has to be by Charles Harris:
> "All this for want of an operator ;)"
I agree this is a good perspective. (But *two* operators: * and **.)
It implies: there are deviations from array behavior that
are buying us nothing. This is my point.
Cheers,
Alan
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