Hi, How sparse are A, x and Ax? You probably will not find any time or operation efficiency unless A and x are relatively sparse. With the small size of n, any efficiency will typically be small in any case.
As you indicate that this has to be repeated multiple times, perhaps you should look at your overall algorithm for efficiencies. Bruce On Dec 14, 2007 3:44 AM, dmitrey <[EMAIL PROTECTED]> wrote: > I guess it doesn't matter, but typical n are 1...1000. > However, I need to call the operation hundreds or thousands times (while > running NLP solver ralg, so 4..5 * nIter times). > Number of zeros can be 0...n-1 > > Charles R Harris wrote: > > How big is n? > > > > On Dec 14, 2007 1:24 AM, dmitrey <[EMAIL PROTECTED] > > <mailto:[EMAIL PROTECTED]>> wrote: > > > > Hi all, > > I have to get Ax, A is n x n matrix, x is vector of length n. > > Some coords of x are zeros, so I want to economy time/cputime somehow > > w/o connecting sparse module from scipy. > > What's the easiest way to do so? > > > > Thx, D. > > _______________________________________________ > > Numpy-discussion mailing list > > [email protected] <mailto:[email protected]> > > http://projects.scipy.org/mailman/listinfo/numpy-discussion > > > > > > ------------------------------------------------------------------------ > > > > > _______________________________________________ > > Numpy-discussion mailing list > > [email protected] > > http://projects.scipy.org/mailman/listinfo/numpy-discussion > > > > _______________________________________________ > Numpy-discussion mailing list > [email protected] > http://projects.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
