BLAS/SRC/ztrmm.f(3)

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💅 BLAS/SRC/ztrmm.f(3) — from the Library Functions Manual, bestie

okay so picture this: it's BLAS/SRC/ztrmm.f(3), and the manual it lives in is literally called the Library Functions Manual. Cute. Let's get into it ✨

🎀 NAME 🎀

BLAS/SRC/ztrmm.f — that's the whole name, that's the whole vibe. This is the manpage for the file that holds ztrmm. 🦋

✨ SYNOPSIS ✨

Functions/Subroutines

  • subroutine ztrmm (side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb) — the one and only ZTRMM 💖

👑 Function/Subroutine Documentation 👑

subroutine ztrmm (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)

ZTRMM 🫶 (yes that's the signature up there, character for character, no cap)

🌸 Purpose 🌸

!> !> ZTRMM performs one of the matrix-matrix operations !> !> B := alpha*op( A )*B, or B := alpha*B*op( A ) !> !> where alpha is a scalar, B is an m by n matrix, 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. !>

so like. it does triangular matrix times matrix things. main character energy fr fr 🔥

🧚 PARAMETERS 🧚

SIDE

!> SIDE is CHARACTER*1 !> On entry, SIDE specifies whether op( A ) multiplies B from !> the left or right as follows: !> !> SIDE = 'L' or 'l' B := alpha*op( A )*B. !> !> SIDE = 'R' or 'r' B := alpha*B*op( A ). !>

left or right, babe — pick your lane 💅

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. !>

upper girlie or lower girlie, your call 🎀

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. !>

no transpose, transpose, or conjugate transpose — the full trio, iconic 🌈

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. !>

is the diagonal all ones or not, that's the whole question 💀

M

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

rows of B. M must be at least zero — don't be out here passing negatives 🙈

N

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

columns of B. also at least zero. rules are rules ✨

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. !>

not me pointing out that if alpha is zero, A doesn't even get looked at and B doesn't need to be set before entry 😭 free pass honestly

A

!> A is COMPLEX*16 array, dimension ( LDA, k ), where k is m !> when SIDE = 'L' or 'l' and 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. !>

so k is m when SIDE = 'L' or 'l', and n when SIDE = 'R' or 'r'. the half you don't need? not referenced, ignored, unbothered 💅 and if DIAG = 'U' or 'u' the diagonal elements aren't referenced either — they're just assumed to be unity. trust.

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 ). !>

leading dimension of A: at least max( 1, m ) for SIDE = 'L' or 'l', at least max( 1, n ) for SIDE = 'R' or 'r'. memorize it, bestie 🍓

B

!> B is COMPLEX*16 array, dimension ( LDB, N ). !> Before entry, the leading m by n part of the array B must !> contain the matrix B, and on exit is overwritten by the !> transformed matrix. !>

B goes in, transformed B comes out. glow-up arc, literally 🌸

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 ). !>

LDB must be at least max( 1, m ). no exceptions, we don't do that here 🔥

💜 Author 💜

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

the whole squad showed up 🫶

⭐ 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. !>

Level 3 BLAS routine, written on 8-February-1989 by Jack Dongarra (Argonne National Laboratory), Iain Duff (AERE Harwell), Jeremy Du Croz (Numerical Algorithms Group Ltd.) and Sven Hammarling (Numerical Algorithms Group Ltd.). legends, honestly 👑

Definition at line 176 of file ztrmm.f. 📍

🌟 Author 🌟

Generated automatically by Doxygen for LAPACK from the source code. (the robot did this one, not me 🤖)

and that's the whole page, bestie! footer tea: this is LAPACK, Version 3.12.0, and the page you just read is BLAS/SRC/ztrmm.f(3). go forth and multiply your triangular matrices 💖✨🎀
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