?getf2

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 10/15/2026

Version

Public

?getf2

Computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

Syntax

lapack_int LAPACKE_sgetf2(int matrix_layout, lapack_int m, lapack_int n, float *a,
                          lapack_int lda, lapack_int *ipiv);

lapack_int LAPACKE_dgetf2(int matrix_layout, lapack_int m, lapack_int n, double *a,
                          lapack_int lda, lapack_int *ipiv);

lapack_int LAPACKE_cgetf2(int matrix_layout, lapack_int m, lapack_int n,
                          lapack_complex_float *a, lapack_int lda, lapack_int *ipiv);

lapack_int LAPACKE_zgetf2(int matrix_layout, lapack_int m, lapack_int n,
                          lapack_complex_double *a, lapack_int lda, lapack_int *ipiv);

Include Files

mkl.h

Description

The routine computes the LU factorization of a general m -by- n matrix A using partial pivoting with row interchanges. The factorization has the form

A = P*L*U

where p is a permutation matrix, L is lower triangular with unit diagonal elements (lower trapezoidal if m > n ) and U is upper triangular (upper trapezoidal if m < n ).

Input Parameters

A <datatype> placeholder, if present, is used for the C interface data types in the C interface section above. See C Interface Conventions for the C interface principal conventions and type definitions.

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

n

The number of columns in A ( n≥ 0 ).

a: REAL for sgetf2 DOUBLE PRECISION for dgetf2 COMPLEX for cgetf2 DOUBLE COMPLEX for zgetf2 . Array, size ( lda ,*). Contains the matrix A to be factored. The second dimension of a must be at least max(1, n) . Array, size at least max(1, lda*n) for column major and max(1, lda*m) for row major layout. Array a contains the m -by- n matrix A .

lda

The leading dimension of a ; at least max(1, m ) for column major layout and max(1, n ) for row major layout .

Output Parameters

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

ipiv

Array, size at least max(1,min(m,n)) . The pivot indices: for 1 ≤ i ≤ n , row i was interchanged with row ipiv(i).

Return Values

This function returns a value info .

If info = -i , the i -th parameter had an illegal value.
If info = i >0 , 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.
If info = -1011 , memory allocation error occurred.

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Developer Reference for Intel® oneAPI Math Kernel Library for C

?getf2

Syntax

Include Files

Description

Input Parameters

Output Parameters

Return Values