Calculates the Moore-Penrose generalized inverse of a matrix
ginv(X, tol = sqrt(.Machine$double.eps))
Matrix for which the Moore-Penrose inverse is required.
A relative tolerance to detect zero singular values.
A MP generalized inverse matrix for X.
Venables, W. N. and Ripley, B. D. (1999)
Modern Applied Statistics with S-PLUS. Third
Edition. Springer. p.100.
solve, svd, eigen