SRC/dgetrs.f(3)

📦
version 3.12.1 · 4 versions
, in arch rolling

💖 SRC/dgetrs.f(3) 💖

okay bestie, this page is from LAPACK's Library Functions Manual and it's all about the DGETRS routine. no cap, it's a little linear-algebra main character moment ✨

💖 NAME 💖

SRC/dgetrs.f — that's the name on the page, periodt. 💅

✨ SYNOPSIS ✨

Functions/Subroutines

       subroutine dgetrs (trans, n, nrhs, a, lda, ipiv, b, ldb, info)
           DGETRS

🧚 Function/Subroutine Documentation 🧚

   subroutine dgetrs (character trans, integer n, integer nrhs, double
       precision, dimension( lda, * ) a, integer lda, integer, dimension( * )
       ipiv, double precision, dimension( ldb, * ) b, integer ldb, integer
       info)

DGETRS — yes bestie, that's the routine name, and here's the tea. 🍵

🎀 Purpose 🎀

DGETRS solves a system of linear equations

A * X = B  or  A**T * X = B

with a general N-by-N matrix A using the LU factorization computed by DGETRF. That's it, that's the whole slay. 💅

💜 Parameters 💜

TRANS

  • TRANS is a CHARACTER*1. It specifies the form of the system of equations, like a vibe check for the equation:
= 'N':  A * X = B  (No transpose)
= 'T':  A**T* X = B  (Transpose)
= 'C':  A**T* X = B  (Conjugate transpose = Transpose)

N

  • N is an INTEGER: the order of the matrix A. N >= 0.

NRHS

  • NRHS is an INTEGER: the number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.

A

  • A is a DOUBLE PRECISION array, dimension (LDA,N). It holds the factors L and U from the factorization A = P*L*U as computed by DGETRF.

LDA

  • LDA is an INTEGER: the leading dimension of the array A. LDA >= max(1,N).

IPIV

  • IPIV is an INTEGER array, dimension (N): the pivot indices from DGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i).

B

  • B is a DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, it's the right hand side matrix B. On exit, it's the solution matrix X.

LDB

  • LDB is an INTEGER: the leading dimension of the array B. LDB >= max(1,N).

INFO

  • INFO is an 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 dgetrs.f.

👑 Author (the auto-gen one) 👑

Generated automatically by Doxygen for LAPACK from the source code.

and the footer sign-off bestie: LAPACK, Version 3.12.0, SRC/dgetrs.f(3) — that's the whole vibe, bye 💖 (no separate date line on this footer)

📦 where this page comes from