CGETRS(3)

🌸 NAME 🌸

Okay bestie, this is the cgetrs.f(3) page from the Library Functions Manual, and the source file it points at is:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cgetrs.f

---

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

The function is literally called CGETRS, and here's the short signature:

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

CGETRS — that's the name, no cap.

🦋 Function/Subroutine Documentation 🦋

Here's the full signature with types and dimensions, exactly as the page gives it:

subroutine CGETRS (character trans, integer n, integer nrhs, complex,
       dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv,
       complex, dimension( ldb, * ) b, integer ldb, integer info)

And yes, the subroutine name is CGETRS again. Main character energy 👑.

🎯 Purpose 🎯

Okay so CGETRS is here to solve a system of linear equations — specifically:

CGETRS solves a system of linear equations
    A * X = B,  A**T * X = B,  or  A**H * X = B
with a general N-by-N matrix A using the LU factorization computed
by CGETRF.

🧸 Parameters 🧸

Every parameter, bestie, no skipping 💅.

💅 TRANS 💅

TRANS is CHARACTER*1. It specifies the form of the system of equations:

• 'N': A * X = B (No transpose)
• 'T': A**T * X = B (Transpose)
• 'C': A**H * X = B (Conjugate transpose)

💅 N 💅

N is INTEGER. The order of the matrix A. N >= 0.

💅 NRHS 💅

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

💅 A 💅

A is COMPLEX array, dimension (LDA,N). The factors L and U from the factorization A = P*L*U as computed by CGETRF.

💅 LDA 💅

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

💅 IPIV 💅

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

💅 B 💅

B is COMPLEX array, dimension (LDB,NRHS). On entry, the right hand side matrix B. On exit, the solution matrix X.

💅 LDB 💅

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

💅 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 cgetrs.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

---

Cute sign-off: this page is LAPACK Version 3.12.0, with footer path /home/abui...RC/cgetrs.f(3) — love that for us 💖✨