SRC/DEPRECATED/dgeqrs.f(3)

🌸 NAME 🌸

SRC/DEPRECATED/dgeqrs.f — this is the file, bestie. The manual name is Library Functions Manual, and the page title is SRC/DEPRECATED/dgeqrs.f(3). No cap, that's the whole NAME section. 💅

✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine dgeqrs (m, n, nrhs, a, lda, tau, b, ldb, work, lwork, info) — the one and only DGEQRS. 👑

🦋 Function/Subroutine Documentation 🦋

subroutine dgeqrs — DGEQRS

Here's the full signature, copied exactly because bestie we do not mess with code:

subroutine dgeqrs (integer m, integer n, integer nrhs, double precision,
       dimension( lda, * ) a, integer lda, double precision, dimension( * )
       tau, double precision, dimension( ldb, * ) b, integer ldb, double
       precision, dimension( lwork ) work, integer lwork, integer info)

This is DGEQRS, periodt. 💖

🎯 Purpose

Solve the least squares problem

min || A*X - B ||

using the QR factorization

A = Q*R

computed by DGEQRF. That's the whole goal, iconic. ✨

🌈 Parameters

Here's the vibe check on every argument, no skips:

• 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. M >= N >= 0. 🌸
• NRHS — NRHS is INTEGER. The number of columns of B. NRHS >= 0. 🎀
• A — A is DOUBLE PRECISION array, dimension (LDA,N). Details of the QR factorization of the original matrix A as returned by DGEQRF. 🦋
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= M. 💜
• TAU — TAU is DOUBLE PRECISION array, dimension (N). Details of the orthogonal matrix Q. 🧚
• B — B is DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, the m-by-nrhs right hand side matrix B. On exit, the n-by-nrhs solution matrix X. 🔥
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= M. 🌈
• WORK — WORK is DOUBLE PRECISION 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 119 of file dgeqrs.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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Sign-off time, bestie: LAPACK Version 3.12.0, page SRC/DEPRECATED/dgeqrs.f(3), generated automatically by Doxygen for LAPACK from the source code. Go off and solve those least squares, you absolute icon. 💖✨🎀