cgetrf.f(3)

✨ NAME ✨

cgetrf.f — that's the name, bestie. also hi, you're in cgetrf.f(3) from the LAPACK manual, and this page is about the cgetrf subroutine. she's lowkey famous. 💅

🌸 SYNOPSIS 🌸

okay so here's the cast list: 🎀

Functions/Subroutines

• subroutine cgetrf (M, N, A, LDA, IPIV, INFO) — CGETRF VARIANT: Crout Level 3 BLAS version of the algorithm.

🎀 Function/Subroutine Documentation 🎀

here's the full signature, exactly as she is, because we do not play with Fortran names in this house: 🫶

subroutine cgetrf (integer M, integer N, complex, dimension( lda, * ) A,
    integer LDA, integer, dimension( * ) IPIV, integer INFO)

CGETRF VARIANT: Crout Level 3 BLAS version of the algorithm.

Purpose:

okay so CGETRF computes an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges. that's the whole assignment. ✨

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). math is mathing. 💅

and yeah, this is the Crout Level 3 BLAS version of the algorithm. periodt. 🔥

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 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 = -i, the i-th argument had an illegal value
  • > 0: if INFO = i, U(i,i) 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.

Date:

December 2016

Definition at line 102 of file VARIANTS/lu/CR/cgetrf.f.

💖 Author 💖

Generated automatically by Doxygen for LAPACK from the source code.

bye bestie!! 💖 LAPACK Version 3.8.0, dated Tue Nov 14 2017, page cgetrf.f(3). 🦋✨