SRC/zgbtrs.f(3)

💅 SRC/zgbtrs.f(3) 💅

okay so bestie, this page is from the Library Functions Manual, and it's giving “LAPACK routine documentation but make it cute.” We're talking about zgbtrs, and yes it is a whole mood. 💖

🎀 NAME 🎀

SRC/zgbtrs.f

✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

• subroutine zgbtrs (trans, n, kl, ku, nrhs, ab, ldab, ipiv, b, ldb, info) — ZGBTRS. that's the whole synopsis, no cap. 🫶

💖 Function/Subroutine Documentation 💖

subroutine zgbtrs (character trans, integer n, integer kl, integer ku,
    integer nrhs, complex*16, dimension( ldab, * ) ab, integer ldab,
    integer, dimension( * ) ipiv, complex*16, dimension( ldb, * ) b, integer
    ldb, integer info)

This subroutine is ZGBTRS. Yep, that's the name, and it serves. ✨

🎯 Purpose

ZGBTRS solves a system of linear equations

A * X = B,  A**T * X = B,  or  A**H * X = B

with a general band matrix A using the LU factorization computed by ZGBTRF. okay so that's the whole purpose, and it ate. 💅

🧚 Parameters

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.

KL

KL is INTEGER. The number of subdiagonals within the band of A. KL >= 0.

KU

KU is INTEGER. The number of superdiagonals within the band of A. KU >= 0.

NRHS

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

AB

AB is COMPLEX*16 array, dimension (LDAB,N). Details of the LU factorization of the band matrix A, as computed by ZGBTRF. U is stored as an upper triangular band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and the multipliers used during the factorization are stored in rows KL+KU+2 to 2*KL+KU+1.

LDAB

LDAB is INTEGER. The leading dimension of the array AB. LDAB >= 2*KL+KU+1.

IPIV

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

B

B is COMPLEX*16 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 136 of file zgbtrs.f.

🌈 Author (Doxygen edition) 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie. This one is LAPACK Version 3.12.0, straight from SRC/zgbtrs.f(3) — mwah 💋