Matlab vs Python (was RE: Discussion: Introducing new operators for matrix computation)

Huaiyu Zhu hzhu at localhost.localdomain
Tue Jul 18 16:07:39 EDT 2000


On Tue, 18 Jul 2000 14:54:10 +0200, Gregory Lielens <gregory.lielens at fft.be>
wrote: 

>I think that it is the more elegant solution if the introduction of new
>operators is rejected...
>This could turn to be even more elegant, if it allow something like
>C = A.I*b  to be equivalent to Matlab's C = A\b, i.e. without any
>inversion of matrix A.

Wait.  Wouldn't this be in fact an operator .I* acting on a and b?  I would
think this is more than the additional operator .* etc.  Module writers
would have a feast on the abundance of supplies.  :-)

>This kind of "retarded" evaluation could even lead to further
>optimizations, and I tink
>that the trace-back problem is avoided if we can ensure that any new
>matrix that is produced and returned
>by an expression evaluation or a function is always in a "blank" state,
>i.e. without any I, T, H,... flag
>on...

Maybe Travis can answer this: how is transpose implemented in NumPy today?
Does it produce a new copy or just changes the indexing?  

Huaiyu



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