[Numpy-discussion] numpy release

Alan G Isaac aisaac@american....
Thu Apr 24 01:31:03 CDT 2008

On Wed, 23 Apr 2008, Bill Spotz apparently wrote:
> Gains: (1) non-scalar extractions from linear algebra 
> objects ARE and BEHAVE like linear algebra objects;

I believe this is not a gain, since there is a standard way to
do this now, which would remain under the second proposal.

> (2) a clear path for dense and sparse matrices to have the 
> same (or at least analogous) interfaces. 

This may prove true.  I'm agnostic.
What actually turns on this?
I believe it is the following:
if iterating over a sparse matrix yields sparse vectors
that behave like a sparse matrix, then iterating over a
matrix should return a vector that behaves like a matrix.
But I have not seen any detailed discussion of this design
issue.  E.g., iterating over a sparse matrix could yield
instead a sparse object that behaves like a 1d array.

I should add that if the first approach is taken,
I agree that it is natural for these "vectors" to
inherit from matrix.

With respect to the matrix object, my only "objection" has 
been that I'd like to hear someone state clearly what 
functionality is gained by following the more complex first 
proposal instead of the second proposal.  The reason: the 
cost of complexity should be justified by a gain in 
functionality.  It *may* be that the link between the 
behavior of matrices and that of sparse matrices is where 
the gain manifests, but that is not yet clear to me.

> Unless I'm misremembering, Alan is the only one who has 
> expressed concerns and he is willing to concede to the 
> design if others agree. 

I'm in no position to concede or not concede anything,
since I am not writing code, but my core concerns
will be met by either proposal.


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