Posted by Lucas du Croo de Jongh on June 03, 1998 at 11:24:51:

In Reply to: Solving matrix eqn. Ax = 0 posted by Chris on April 07, 1998 at 17:28:23:

: I am interested in any routines which can "solve" the matrix eqn. Ax = 0 (A is a singular N by N matrix and x is an N element vector). In my case A is also symmetric, if that is any help.

(I suppose this is the way te reply to questions)

Ax=0

If A is positive definite you can minimize

xAx/(xx)

for instance by conjugate gradient (described in 'numerical recipes' section 10.6)

Otherwise you can of course minimize

xAAx/(xx)

but this will be quite slow.

cheers,

Lucas