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Re: Find position of nonzero elements


On Tue, 19 Jul 2011, Dominic Wörner wrote:

> Hi,
>
> How can I find the indices i and j of all nonzero elements of a matrix.
> I want that because there are only some nonzero elements in a huge
> matrix.
>
> Best regards,
> Dominic

Dominic,

how about

sa = SparseArray[IdentityMatrix[4]]
sa["Properties"]
sa["NonzeroPositions"]

Oliver

>
>


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