No reason. Thanks for the suggestion!
On Saturday, March 7, 2015 at 3:26:00 AM UTC+11, Steven G. Johnson wrote: > > > > On Thursday, March 5, 2015 at 4:58:10 PM UTC-5, Sheehan Olver wrote: >> >> >> Hmm, maybe I’m posing the wrong problem then… I wanted a fast way to >> calculate the null space of a sparse matrix, where the basis spanning the >> null space is also sparse. And the dimension of the vector space is in the >> millions. >> > > In that case, why not use: > > min ||Lx||_1 subject to ||x||_1= 1 (or ||x||_\infty = 1)? > > That can be transformed into an LP. (As I understand it, the only reason > for your norm constraint on x is to prevent the trivial x=0 solution, but > won't any norm work for that?) >
