[SciPy-dev] Trouble with optimize.fmin_ncg

Nathan Bell wnbell@gmail....
Wed Jul 25 13:33:09 CDT 2007


On 7/25/07, Nils Wagner <nwagner@iam.uni-stuttgart.de> wrote:
> Thank you very much! It took me a while to locate
> the bug. Now it works fine again !
> BTW, is there a way to support sparse vectors such
> that the outer product of sparse vectors yields
> a sparse matrix ?

If the vector is represented as an Nx1 sparse matrix V, then the outer
product is simply V*V.T.  Likewise if V is 1xN then the outer product
is V.T*V.  The existing sparse matrix multiplication code should do
these operations efficiently.


-- 
Nathan Bell wnbell@gmail.com


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