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Ublas :

From: Karl Meerbergen (Karl.Meerbergen_at_[hidden])
Date: 2005-12-19 10:43:56

Eddie Vedder wrote:

>>The determinant is
>>usually computed from the LU factorization: compute the product of the
>>diagonal of U and you have the determinant.
>I computed the LU factorisation of the matrix with ATLAS bindings function
>lu_factor(A,ipiv) where A holds the LU factorisation. The problem is, that
>the product of the diagonal results in a determinant with wrong sign. I
>found out, this has to do with the pivoting. How can I find out the correct
>sign of the determinant?

I do not know the function lu_factor. Pivoting should not change the
value of the product of the diagonal elts, unless 2x2 pivots are present
(for symmetric matrices).