BLAS/SRC/ztrsm.f(3)

💖 ztrsm — BLAS/SRC/ztrsm.f 💖

okay bestie, welcome to the LAPACK manual page for BLAS/SRC/ztrsm.f, and no cap, this one is a baddie. it's a Level 3 BLAS routine and it's out here solving triangular matrix equations like it's literally nothing. let's get into it 🫶

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✨ NAME ✨

BLAS/SRC/ztrsm.f

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🌸 SYNOPSIS 🌸

Functions/Subroutines

• subroutine ztrsm (side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb) — ZTRSM

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🦋 Function/Subroutine Documentation 🦋

subroutine ztrsm (character side, character uplo, character transa, character diag, integer m, integer n, complex*16 alpha, complex*16, dimension(lda,*) a, integer lda, complex*16, dimension(ldb,*) b, integer ldb)

ZTRSM

🎀 Purpose:

ZTRSM solves one of the matrix equations

op( A )*X = alpha*B,   or   X*op( A ) = alpha*B,

where alpha is a scalar, X and B are m by n matrices, A is a unit, or non-unit, upper or lower triangular matrix and op( A ) is one of

op( A ) = A   or   op( A ) = A**T   or   op( A ) = A**H.

The matrix X is overwritten on B. yes, B gets eaten, that's just how it is 💅

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⭐ Parameters ⭐

• SIDE

SIDE is CHARACTER*1 On entry, SIDE specifies whether op( A ) appears on the left or right of X as follows:

SIDE = 'L' or 'l'   op( A )*X = alpha*B.

SIDE = 'R' or 'r'   X*op( A ) = alpha*B.

• UPLO

UPLO is CHARACTER*1 On entry, UPLO specifies whether the matrix A is an upper or lower triangular matrix as follows:

UPLO = 'U' or 'u'   A is an upper triangular matrix.

UPLO = 'L' or 'l'   A is a lower triangular matrix.

• TRANSA

TRANSA is CHARACTER*1 On entry, TRANSA specifies the form of op( A ) to be used in the matrix multiplication as follows:

TRANSA = 'N' or 'n'   op( A ) = A.

TRANSA = 'T' or 't'   op( A ) = A**T.

TRANSA = 'C' or 'c'   op( A ) = A**H.

• DIAG

DIAG is CHARACTER*1 On entry, DIAG specifies whether or not A is unit triangular as follows:

DIAG = 'U' or 'u'   A is assumed to be unit triangular.

DIAG = 'N' or 'n'   A is not assumed to be unit
                    triangular.

• M

M is INTEGER On entry, M specifies the number of rows of B. M must be at least zero.

• N

N is INTEGER On entry, N specifies the number of columns of B. N must be at least zero.

• ALPHA

ALPHA is COMPLEX*16 On entry, ALPHA specifies the scalar alpha. When alpha is zero then A is not referenced and B need not be set before entry. free real estate, we love to see it ✨

• A

A is COMPLEX*16 array, dimension ( LDA, k ), where k is m when SIDE = 'L' or 'l' and k is n when SIDE = 'R' or 'r'. Before entry with UPLO = 'U' or 'u', the leading k by k upper triangular part of the array A must contain the upper triangular matrix and the strictly lower triangular part of A is not referenced. Before entry with UPLO = 'L' or 'l', the leading k by k lower triangular part of the array A must contain the lower triangular matrix and the strictly upper triangular part of A is not referenced. Note that when DIAG = 'U' or 'u', the diagonal elements of A are not referenced either, but are assumed to be unity. she's unit triangular, she doesn't need a diagonal, she's built different 💜

• LDA

LDA is INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When SIDE = 'L' or 'l' then LDA must be at least max( 1, m ), when SIDE = 'R' or 'r' then LDA must be at least max( 1, n ).

• B

B is COMPLEX*16 array, dimension ( LDB, N ) Before entry, the leading m by n part of the array B must contain the right-hand side matrix B, and on exit is overwritten by the solution matrix X.

• LDB

LDB is INTEGER On entry, LDB specifies the first dimension of B as declared in the calling (sub) program. LDB must be at least max( 1, m ).

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👑 Author 👑

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

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🔥 Further Details: 🔥

• Level 3 Blas routine.
• ``` -- Written on 8-February-1989. Jack Dongarra, Argonne National Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms Group Ltd.

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Definition at line **179** of file `ztrsm.f`. <cyan>iykyk 📍</cyan>

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# 🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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> <rainbow>that's the whole page, bestie — every flag, every dimension, every single `'L'` and `'l'` accounted for. go forth and solve those triangular systems 💖</rainbow>

<pink>**Version 3.12.0**</pink> · <purple>Tue Nov 28 2023 12:08:41</purple> · `BLAS/SRC/ztrsm.f(3)` — mwah, stan LAPACK, periodt 🎀✨