SciPy

scipy.linalg.lu

scipy.linalg.lu(a, permute_l=False, overwrite_a=False, check_finite=True)[source]

Compute pivoted LU decompostion of a matrix.

The decomposition is:

A = P L U

where P is a permutation matrix, L lower triangular with unit diagonal elements, and U upper triangular.

Parameters :

a : (M, N) array_like

Array to decompose

permute_l : bool

Perform the multiplication P*L (Default: do not permute)

overwrite_a : bool

Whether to overwrite data in a (may improve performance)

check_finite : boolean, optional

Whether to check that the input matrix contains only finite numbers. Disabling may give a performance gain, but may result in problems (crashes, non-termination) if the inputs do contain infinities or NaNs.

Returns :

**(If permute_l == False)** :

p : (M, M) ndarray

Permutation matrix

l : (M, K) ndarray

Lower triangular or trapezoidal matrix with unit diagonal. K = min(M, N)

u : (K, N) ndarray

Upper triangular or trapezoidal matrix

**(If permute_l == True)** :

pl : (M, K) ndarray

Permuted L matrix. K = min(M, N)

u : (K, N) ndarray

Upper triangular or trapezoidal matrix

Notes

This is a LU factorization routine written for Scipy.