mkl_?getrfnp

Developer Reference for Intel® oneAPI Math Kernel Library for C

Download PDF

ID 766684

Date 10/15/2026

Version

Public

mkl_?getrfnp

Computes the LU factorization of a general m-by-n matrix without pivoting.

Syntax

lapack_int LAPACKE_mkl_sgetrfnp(int matrix_layout, lapack_int m, lapack_int n, float *a,
                                lapack_int lda);

lapack_int LAPACKE_mkl_dgetrfnp(int matrix_layout, lapack_int m, lapack_int n, double *a,
                                lapack_int lda);

lapack_int LAPACKE_mkl_cgetrfnp(int matrix_layout, lapack_int m, lapack_int n,
                                lapack_complex_float *a, lapack_int lda);

lapack_int LAPACKE_mkl_zgetrfnp(int matrix_layout, lapack_int m, lapack_int n,
                                lapack_complex_double *a, lapack_int lda);

Include Files

mkl.h

Description

mkl_sgetrfnp mkl_dgetrfnp mkl_cgetrfnp mkl_zgetrfnp getrf

The routine computes the LU factorization of a general m -by- n matrix A as

A = L*U ,

where L is lower triangular with unit-diagonal elements (lower trapezoidal if m > n ) and U is upper triangular (upper trapezoidal if m < n ). The routine does not use pivoting.

Input Parameters

matrix_layout

Specifies whether matrix storage layout is row major ( LAPACK_ROW_MAJOR ) or column major ( LAPACK_COL_MAJOR ).

m: The number of rows in the matrix A. The value of m must be at least zero.

n: The number of columns in the matrix A. The value of n must be at least zero.

a

Array, size at least max(1, lda * n ) for column-major layout or max(1, lda * m ) for row-major layout . Contains the matrix A .

lda: INTEGER. The leading dimension of array a , which must be at least max(1, m ) for column-major layout or max(1, n ) for row-major layout .

Output Parameters

a

Overwritten by L and U . The unit diagonal elements of L are not stored.

Return Values

This function returns a value info .

If info=0 , the execution is successful.
If info = -i , parameter i had an illegal value.
If info = i , \(u_{ii}\) is 0. The factorization has been completed, but U is exactly singular. Division by 0 will occur if you use the factor U for solving a system of linear equations.

Application Notes

The approximate number of floating-point operations for real flavors is

\((2/3)n^{3}\) if m = n,
\((1/3) n^2 (3m - n)\) if m>n, or
\((1/3) m^2 (3n - m)\) if m<n.

The number of operations for complex flavors is four times greater.

After calling this routine with m = n , you can call the following:

mkl_?getrinp (Computes the inverse of an LU-factored general matrix without pivoting.) to compute the inverse of \(A\)

NOTE:

Select Your Language

Using Intel.com Search

Quick Links

Recent Searches

Advanced Search

Only search in

Developer Reference for Intel® oneAPI Math Kernel Library for C

mkl_?getrfnp

Syntax

Include Files

Description

Input Parameters

Output Parameters

Return Values

Application Notes