kernel - kernel, nullspace
W=kernel(A) returns the kernel (nullspace) of A . If A has full column rank then an empty matrix [] is returned.
flag and tol are optional parameters: flag = 'qr' or 'svd' (default is 'svd' ).
tol = tolerance parameter (of order %eps as default value).
A=rand(3,1)*rand(1,3); A*kernel(A) A=sparse(A); clean(A*kernel(A))
colcomp , fullrf , fullrfk , linsolve ,
F.D.;