SGEQLS(3)

💅 SGEQLS(3) — Library Functions Manual 💅

okay so bestie, welcome to the Library Functions Manual page for SGEQLS(3). It’s giving LAPACK subroutine energy, and we’re gonna keep every detail intact. No cap. ✨

---

✨ NAME ✨

literally the NAME section is just this path, and I’m not changing a single character:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/sgeqls.f

---

🦋 SYNOPSIS 🦋

Functions/Subroutines

The short subroutine vibe is:

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

and yes, it just says SGEQLS after that. Iconic little name tag behavior 💅.

Function/Subroutine Documentation

Here’s the full signature, character for character:

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)

Then the docs just say SGEQLS again. main character energy 🎀.

Purpose

The purpose block is literally this, and it’s solving the least squares problem with the QL factorization from SGEQLF:

!>
!> Solve the least squares problem
!>     min || A*X - B ||
!> using the QL factorization
!>     A = Q*L
!> computed by SGEQLF.
!>

Parameters

• M — M is INTEGER. It’s the number of rows of the matrix A. Constraint: M >= 0. 🌸
• N — N is INTEGER. It’s the number of columns of the matrix A. Constraint: M >= N >= 0. 💖
• NRHS — NRHS is INTEGER. It’s the number of columns of B. Constraint: NRHS >= 0. ✨
• A — A is REAL array, dimension (LDA,N). It holds details of the QL factorization of the original matrix A as returned by SGEQLF. 🦋
• LDA — LDA is INTEGER. It’s the leading dimension of the array A. Constraint: LDA >= M. 💅
• TAU — TAU is REAL array, dimension (N). It holds details of the orthogonal matrix Q. 🎀
• 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. 🔥
• LDB — LDB is INTEGER. It’s the leading dimension of the array B. Constraint: LDB >= M. 🌈
• WORK — WORK is REAL array, dimension (LWORK). 🫶
• 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. ⭐
• INFO — INFO is INTEGER. Status tea: = 0: successful exit; < 0: if INFO = -i, the i-th argument had an illegal value. 💀

Author

Shoutout to the institutions on this one:

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

And the exact line: Definition at line 120 of file sgeqls.f. 👑

---

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. periodt. 💖

---

💖 cute sign-off: this page is LAPACK, Version 3.12.0, and its footer path is /home/abui...IN/sgeqls.f(3) — there’s literally no date on the page, so I’m not inventing one, bestie. 🫶