MASS (version 7.3-47)

ginv:

Description

Calculates the Moore-Penrose generalized inverse of a matrix X.

Usage

ginv(X, tol = sqrt(.Machine$double.eps))

Arguments

X

Matrix for which the Moore-Penrose inverse is required.

tol

A relative tolerance to detect zero singular values.

Value

A MP generalized inverse matrix for X.

References

Venables, W. N. and Ripley, B. D. (1999) Modern Applied Statistics with S-PLUS. Third Edition. Springer. p.100.

See Also

solve, svd, eigen

Examples

## Not run: ------------------------------------
# # The function is currently defined as
# function(X, tol = sqrt(.Machine$double.eps))
# {
# ## Generalized Inverse of a Matrix
#   dnx <- dimnames(X)
#   if(is.null(dnx)) dnx <- vector("list", 2)
#   s <- svd(X)
#   nz <- s$d > tol * s$d[1]
#   structure(
#     if(any(nz)) s$v[, nz] %*% (t(s$u[, nz])/s$d[nz]) else X,
#     dimnames = dnx[2:1])
# }
## ---------------------------------------------