X = PINV(A) produces a matrix X of the same dimensions
as A' so that A*X*A = A, X*A*X = X and AX and XA
are Hermitian. The computation is based on SVD (A) and any
singular values less than a tolerance are treated as zero.
The default tolerance is MAX (SIZE (A)) * NORM (A) * EPS .
This tolerance may be overridden with X = PINV(A,tol).
See also RANK1DJZJU2.