Re: [sympy] Re: why eigenvectors very slow

2018-10-04 Thread Jacob Miner
On Friday, July 10, 2015 at 3:07:17 PM UTC-6, Ondřej Čertík wrote: > > Hi, > > On Fri, Jul 10, 2015 at 7:30 AM, 刘金国 > > wrote: > > 4 x 4 is needed ~~ > > mathematica runs extremely fast for 4 x 4 matrix as it should be, but > ... > > Can you post the Mathematica result? So that we know

Re: [sympy] Re: why eigenvectors very slow

2018-10-09 Thread Jacob Miner
to cancel each other out in > the result, this can be detrimental. > > I would start with the eigenvalues. Once you can get those, you will > want to simplify them if possible, before computing the eigenvectors. > > Aaron Meurer > On Thu, Oct 4, 2018 at 6:12 PM Jacob Miner &

Re: [sympy] Re: why eigenvectors very slow

2018-10-09 Thread Jacob Miner
I think I understand, but is there an implementation of this technique that can actually perform the linear algebra on a symbolic matrix at such improved compute-time? On Tuesday, October 9, 2018 at 1:58:04 PM UTC-6, Isuru Fernando wrote: > > First k-1 entries of the k th eigenvector for an

Re: [sympy] Re: why eigenvectors very slow

2018-10-09 Thread Jacob Miner
; > Hi, > > > > For triangular matrices, it's straightforward to calculate eigenvectors. > You just need triangular solves. See Section 4.4.1 of Heath's Scientific > Computing 2nd Edition. > > > > Isuru > > > > On Tue, Oct 9, 2018 at 11:27 AM Jacob Min