Determinant of Large Matrix

[montyphyton at gmail.com]

James Stroud je napisao/la:
> Hello All,
>
> I'm using numpy to calculate determinants of matrices that look like
> this (13x13):
>
> [[ 0.  1.  1.  1.  1.  1.  1.  1.  1.  1.  1.  1.  1.  1.]
>   [ 1.  0.  1.  4.  1.  9.  4.  4.  1.  1.  4.  9.  4.  9.]
>   [ 1.  1.  0.  1.  4.  4.  9.  9.  4.  4.  1.  4.  1.  4.]
>   [ 1.  4.  1.  0.  9.  1.  4.  4.  9.  1.  4.  1.  4.  1.]
>   [ 1.  1.  4.  9.  0.  4.  4.  4.  1.  4.  1.  9.  4.  9.]
>   [ 1.  9.  4.  1.  4.  0.  4.  4.  9.  4.  1.  1.  4.  1.]
>   [ 1.  4.  9.  4.  4.  4.  0.  1.  1.  1.  9.  1.  9.  4.]
>   [ 1.  4.  9.  4.  4.  4.  1.  0.  4.  1.  9.  4.  4.  1.]
>   [ 1.  1.  4.  9.  1.  9.  1.  4.  0.  4.  4.  4.  4.  9.]
>   [ 1.  1.  4.  1.  4.  4.  1.  1.  4.  0.  9.  4.  9.  4.]
>   [ 1.  4.  1.  4.  1.  1.  9.  9.  4.  9.  0.  4.  1.  4.]
>   [ 1.  9.  4.  1.  9.  1.  1.  4.  4.  4.  4.  0.  4.  1.]
>   [ 1.  4.  1.  4.  4.  4.  9.  4.  4.  9.  1.  4.  0.  1.]
>   [ 1.  9.  4.  1.  9.  1.  4.  1.  9.  4.  4.  1.  1.  0.]]
>
> For this matrix, I'm getting this with numpy:
>
>   2774532095.9999971
>
> But I have a feeling I'm exceeding the capacity of floats here. Does
> anyone have an idea for how to treat this? Is it absurd to think I could
> get a determinant of this matrix? Is there a python package that could
> help me?
>
> Many thanks for any answers.
>
> James

have you tried using matlab to verify the result? matlab is very fast
and can work with large matrices, so this should be no problem for
it...