On Monday, February 10, 2014 11:27:09 PM UTC-5, monde wilson wrote: > > why eigenvectors very slow > > what is the difference between numpy and sympy when doing matrix > calculation >
Sympy calculates eigenvectors symbolically (thus exactly), numpy calculates them numerically using floating point arithmetic. In general you don't want to use sympy to calculate the eigenvectors for matrices larger than 2x2, because the symbolic results can be very complicated. (IIRC, the eigenvalues are calculated by finding roots of the characteristic polynomial, which can lead to nasty expressions for dimension 3 and beyond.) > will numpy faster and more accurately > Numpy will be a lot faster, but not more accurate. If you only need numerical results, you probably should use numpy for this. Vinzent -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
