[Help-gsl] SVD with GSL outperformed by MatLab by a factor of 10

[Kalb Max]

 Hi,

we compared the GSL-svd to MatLab and found an order of magnitude in 
time performance in favor of MAtLab nearly independent of the matrix 
sizes. We tried 100x52 up to 2000x52 as dimensions of the real matrices, 
which are not sparse.
For a 800x 52 matrix  we have 210 ms with GSL and 7 ms with MatLab for 
the svd for the following commands:

gsl_linalg_SV_decomp_mod(Atempm, X, Vm, S, work)
gsl_blas_dgemm(CblasNoTrans, CblasNoTrans, 1.0, Vm, SiD, 0.0, VSiD);
gsl_blas_dgemm(CblasNoTrans, CblasTrans, 1.0, VSiD, Atempm, 0.0, MoIm);

We work with:
Intel(R) Core(TM)2 Duo CPU E6850 @ 3.00 GHz, 2 GB RAM
WinXP S3
Visual Studio 2005
GSL 1.12

We could live with less precise singular values, since we throw away the 
smallest ones. Additionally, we do not need the according vectors of the 
U-matrix.

Any idead how to improve the GSL version?

Thanks a lot!

Max

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