[Numpy-discussion] Getting 0.9.8 out this week

[Alan G Isaac]

>> On Tue, 09 May 2006, Tim Hochberg apparently wrote: 
>>> Let's start with the example in the ticket: 
>>>     >>> m.argmax() 
>>>    matrix([[8]]) 
>>> Does anyone else think that this is a fairly nonsensical result? 

> Alan G Isaac wrote: 
>> Yes. The result should be a scalar. 

On Tue, 09 May 2006, Tim Hochberg apparently wrote: 
> Why? The current behaviour is both more self consistent and easier to 
> explain, so it would be nice to see some examples of how a scalar would 
> be advantageous here. 

Because that is the result for array.
For consistency, I think
m.argmax()
m.A.argmax()
should be equivalent.
(Also along axes, and therefore never returning matrices.
And let ravel really ravel it, rather than duplicating hstack!
What is the principal at work: must matrices always produce
matrices almost no matter what we do with them?
I prefer the principle that standard matrix operations
on matrices return matrices. But then, I see I am not ready to
be consistent, as I do want m.max(num) to be a matrix ... )

> Now if a.argmax() returned (2, 2) in this case, that would 
> be useful

Agreed.
I should not have implied that a scalar return is "better" 
than a tuple in this case.  But this seems a radical change   
in behavior.  If this is the behavior desired in this case, 
does that not suggest a behavior change for every case? That 
is, are you not in effect arguing that argmax should some 
kind of indexing object such that
a.max(num) == a[a.argmax(num)]
This seems quite useful but entirely new.

Cheers,
Alan Isaac