matrix.lubksb

Syntax

m = matrix.lubksb(v,a)

Get the LU decomposition via backwards substitution. The LU decomposition is a factorization of v as the product of lower-triangular and upper-triangular matrices. v is converted to a matrix and must be square. a, the pivot vector, must be a one-dimensional array with the number of rows equal to the number of rows/columns in v. The pivot vector shows the row interchanges. The lower-triangular matrix is the lower-triangular portion of m with ones along the diagonal. The upper-diagonal matrix is the upper-diagonal portion of m.

Returns:m - Composite LU factorization matrix. The lower-triangular matrix is the lower-triangular portion of m with ones along the diagonal. The upper-diagonal matrix is the upper-diagonal portion of m. Arguments:v - array, matrix, or tensor pointer corresponding to a square matrix