SRC/zgetf2.f(3)

🌸 NAME 🌸

okay so bestie, this is SRC/zgetf2.f(3) from the Library Functions Manual — the page for zgetf2, aka the unblocked LU factorization girlie. She’s out here factoring a general m-by-n matrix using partial pivoting with row interchanges, and honestly? iconic. 💅

✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine zgetf2 (m, n, a, lda, ipiv, info) — ZGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm). 🫶

🦋 Function/Subroutine Documentation 🦋

subroutine zgetf2 🎀

subroutine zgetf2 (integer m, integer n, complex*16, dimension( lda, * ) a,
       integer lda, integer, dimension( * ) ipiv, integer info)

ZGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm). Periodt. 💜

Purpose 🎯

okay so ZGETF2 computes an 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).

This is the right-looking Level 2 BLAS version of the algorithm. No cap, she’s right-looking and proud. 🔥

Parameters 🧸

M

M is INTEGER. The number of rows of the matrix A. M >= 0.

N

N is INTEGER. The number of columns of the matrix A. N >= 0.

A

A is COMPLEX*16 array, dimension (LDA,N). On entry, the m by n matrix to be factored. On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored.

LDA

LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,M).

IPIV

IPIV is INTEGER array, dimension (min(M,N)). The pivot indices; for 1 <= i <= min(M,N), row i of the matrix was interchanged with row IPIV(i).

INFO

INFO is INTEGER.

• = 0: successful exit
• < 0: if INFO = -k, the k-th argument had an illegal value
• > 0: if INFO = k, U(k,k) is exactly zero. The factorization has been completed, but the factor U is exactly singular, and division by zero will occur if it is used to solve a system of equations.

💖 Author 💖

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Definition at line 107 of file zgetf2.f

bestie, this is where she lives: line 107 of zgetf2.f. 🧚

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

---

that’s the footer, bestie — LAPACK, Version 3.12.0, SRC/zgetf2.f(3). mwah 💋