TESTING/LIN/sgerqs.f(3)

📦
version 3.12.1 · 2 versions
, in arch rolling

✨ NAME ✨

This is the TESTING/LIN/sgerqs.f(3) page from the Library Functions Manual — aka the manual page for TESTING/LIN/sgerqs.f. Bestie, it’s all about the sgerqs subroutine. 💖

🦋 SYNOPSIS 🦋

🧚 Functions/Subroutines 🧚

subroutine sgerqs (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info)
    SGERQS

🌈 Function/Subroutine Documentation 🌈

   subroutine sgerqs (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)

SGERQS — iconic, all caps, here to solve the problem. 👑

🎯 Purpose

Compute a minimum-norm solution

min || A*X - B ||

using the RQ factorization

A = R*Q

computed by SGERQF. Slay. 💅

🎀 Parameters 🎀

  • M — M is INTEGER. The number of rows of the matrix A. Constraint: M >= 0. ✨
  • N — N is INTEGER. The number of columns of the matrix A. Constraint: N >= M >= 0. 🦋
  • NRHS — NRHS is INTEGER. The number of columns of B. Constraint: NRHS >= 0. 🌸
  • A — A is REAL array, dimension (LDA,N). Details of the RQ factorization of the original matrix A as returned by SGERQF. 💖
  • LDA — LDA is INTEGER. The leading dimension of the array A. Constraint: LDA >= M. 🎀
  • TAU — TAU is REAL array, dimension (M). Details of the orthogonal matrix Q. 💫
  • B — B is REAL array, dimension (LDB,NRHS). On entry, the right hand side vectors for the linear system. On exit, the solution vectors X. Each solution vector is contained in rows 1:N of a column of B. 🌈
  • LDB — LDB is INTEGER. The leading dimension of the array B. Constraint: LDB >= max(1,N). 🫶
  • WORK — WORK is REAL array, dimension (LWORK). 🧚
  • LWORK — LWORK is INTEGER. 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. 🔥
  • INFO — INFO is INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. 💀

👑 Author 👑

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

Definition at line 120 of file sgerqs.f. 📌

🪄 Author 🪄

Generated automatically by Doxygen for LAPACK from the source code. 🤖✨

Source/version check: LAPACK Version 3.12.0, page TESTING/LIN/sgerqs.f(3). The footer doesn’t print a date on this page, so I’m not gonna invent one — no cap. 🫶💅

📦 where this page comes from