DGETF2(3)

💅 DGETF2(3) — LU factorization, unblocked edition ✨

okay bestie, welcome to the Library Functions Manual 💖 this page is literally all about DGETF2, and it’s giving “small but mighty Level 2 BLAS icon” energy no cap ✨

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📛 NAME

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/dgetf2.f — that’s the file, bestie 🫶 and the subroutine living there is DGETF2, which computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

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🌸 SYNOPSIS

Functions/Subroutines

subroutine DGETF2 (m, n, a, lda, ipiv, info)

DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

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🧚 Function/Subroutine Documentation

   subroutine DGETF2 (integer m, integer n, double precision, dimension( lda, *
       ) a, integer lda, integer, dimension( * ) ipiv, integer info)

DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

🎯 Purpose

okay so here’s the main character moment 👑 DGETF2 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. 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 DOUBLE PRECISION 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 dgetf2.f.

👑 Author

Generated automatically by Doxygen for LAPACK from the source code.

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that’s the whole page, bestie 🫶 this is LAPACK Version 3.12.0, source path /home/abui...RC/dgetf2.f(3) 💖 no date printed on this one, so I’m not gonna invent one 😭 stay iconic and go factor something slay ✨