matrix multiplication

[Daniel T Konkle]

I need to implement  S = A' * A  where A' is the transpose of A.

Is it possible to do it like this:

gsl_blas_dgemm( CblasTrans, CblasNoTrans, 1.0, A, A, 0.0, S );

or do I need to copy the contents of a into a temporary matrix first

gsl_matrix_memcpy( B, A );
gsl_blas_dgemm( CblasTrans, CblasNoTrans, 1.0, A, B, 0.0, S );

Thanks,
Danny