?getf2

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

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

call sgetf2(m, n, a, lda, ipiv, info)
call dgetf2(m, n, a, lda, ipiv, info)
call cgetf2(m, n, a, lda, ipiv, info)
call zgetf2(m, n, a, lda, ipiv, info)

Include Files

mkl.fi

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

The data types are given for the Fortran interface.

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

n

INTEGER . 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

INTEGER . The leading dimension of a ; at least max(1, m ) .

Output Parameters

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

ipiv

INTEGER .

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

info

INTEGER .

If info=0 , the execution is successful.
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.

Return Values

No return value, info is an Output Parameter.

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

?getf2

Syntax

Include Files

Description

Input Parameters

Output Parameters

Return Values