TESTING/LIN/sgeqls.f(3)

📦
version 3.12.1 · 2 versions
, in arch rolling

🌸 NAME 🌸

TESTING/LIN/sgeqls.f — bestie, this is straight out of the Library Functions Manual, and it’s giving iconic LAPACK testing-file energy. No cap.

✨ SYNOPSIS ✨

Functions/Subroutines

  • subroutine sgeqls (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info) — SGEQLS

💖 Function/Subroutine Documentation 💖

subroutine sgeqls (integer m, integer n, integer nrhs, real, dimension( lda,
* ) a, integer lda, real, dimension( * ) tau, real, dimension( ldb, * )
b, integer ldb, real, dimension( lwork ) work, integer lwork, integer
info)

SGEQLS

🦋 Purpose 🦋

Okay so the whole point, bestie: solve the least squares problem

min || A*X - B ||

using the QL factorization

A = Q*L

computed by SGEQLF. Periodt. 💅

🎀 Parameters 🎀

  • M — M is INTEGER. It’s the number of rows of the matrix A. Constraint: M >= 0. Respect the boundary, queen. ✨
  • N — N is INTEGER. It’s the number of columns of the matrix A. Constraint: M >= N >= 0. Yes, that’s the chain, fr fr.
  • NRHS — NRHS is INTEGER. It’s the number of columns of B. Constraint: NRHS >= 0. Keep it non-negative, bestie. 💖
  • A — A is REAL array, dimension (LDA,N). It holds details of the QL factorization of the original matrix A as returned by SGEQLF. Lowkey important. 👑
  • LDA — LDA is INTEGER. It’s the leading dimension of the array A. Constraint: LDA >= M. Do not play with this. 🫶
  • TAU — TAU is REAL array, dimension (N). It holds details of the orthogonal matrix Q. Iconic auxiliary energy. 🌈
  • B — B is REAL array, dimension (LDB,NRHS). On entry, it’s the m-by-nrhs right hand side matrix B. On exit, it’s the n-by-nrhs solution matrix X, stored in rows m-n+1:m. The way it transforms… character development. 💫
  • LDB — LDB is INTEGER. It’s the leading dimension of the array B. Constraint: LDB >= M. Respect the leading dimension, pls. 💜
  • WORK — WORK is REAL array, dimension (LWORK). Workspace vibes only. 🧚
  • LWORK — LWORK is INTEGER. It’s the length of the array WORK. LWORK must be at least NRHS, and should be at least NRHS*NB, where NB is the block size for this environment. So like… don’t under-feed the workspace. 😭
  • INFO — INFO is INTEGER. Exit-status tea:
    • = 0: successful exit. Slay. ✅
    • < 0: if INFO = -i, the i-th argument had an illegal value. Read the number, bestie. 💀

🫶 Author 🫶

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 120 of file sgeqls.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

💜 That’s the whole page, bestie: LAPACK Version 3.12.0, page TESTING/LIN/sgeqls.f(3), and the footer energy is right there. Mwah! 💋✨

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