SRC/clapmr.f(3)

💅 SRC/clapmr.f — from the Library Functions Manual 🎀

okay bestie, settle in, because this one is a Fortran subroutine page and honestly? she's iconic. it's SRC/clapmr.f, and it does exactly one thing but does it so well. ✨

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✨ NAME ✨

SRC/clapmr.f — the file where clapmr lives, and the whole page is basically her whole personality.

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🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine clapmr (forwrd, m, n, x, ldx, k)

CLAPMR rearranges rows of a matrix as specified by a permutation vector. that's it. that's the tweet. 🐦

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🦋 Function/Subroutine Documentation 🦋

subroutine clapmr (logical forwrd, integer m, integer n, complex, dimension(
    ldx, * ) x, integer ldx, integer, dimension( * ) k)

CLAPMR rearranges rows of a matrix as specified by a permutation vector. no cap, that is genuinely her entire job description.

🎯 Purpose:

!>
!> CLAPMR rearranges the rows of the M by N matrix X as specified
!> by the permutation K(1),K(2),...,K(M) of the integers 1,...,M.
!> If FORWRD = .TRUE.,  forward permutation:
!>
!>      X(K(I),*) is moved X(I,*) for I = 1,2,...,M.
!>
!> If FORWRD = .FALSE., backward permutation:
!>
!>      X(I,*) is moved to X(K(I),*) for I = 1,2,...,M.
!>

so like — if FORWRD = .TRUE., it's a forward permutation, and X(K(I),*) is moved X(I,*) for I = 1,2,...,M.

and if FORWRD = .FALSE., it's a backward permutation, and X(I,*) is moved to X(K(I),*) for I = 1,2,...,M. she's reversible, she's flexible, she contains multitudes 💖

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👑 Parameters 👑

FORWRD

!>          FORWRD is LOGICAL
!>          = .TRUE., forward permutation
!>          = .FALSE., backward permutation
!>

the vibe check switch: .TRUE. means forward permutation, .FALSE. means backward permutation. pick your fighter ⚔️

M

!>          M is INTEGER
!>          The number of rows of the matrix X. M >= 0.
!>

the number of rows of the matrix X, and the constraint is literally M >= 0. zero is allowed, bestie, we don't gatekeep 🫶

N

!>          N is INTEGER
!>          The number of columns of the matrix X. N >= 0.
!>

the number of columns of the matrix X, and again N >= 0. same energy, same allowance ✨

X

!>          X is COMPLEX array, dimension (LDX,N)
!>          On entry, the M by N matrix X.
!>          On exit, X contains the permuted matrix X.
!>

X is a COMPLEX array with dimension (LDX,N). on entry she's the M by N matrix X; on exit she's the permuted matrix X. glow-up was internal, results are external 💅

LDX

!>          LDX is INTEGER
!>          The leading dimension of the array X, LDX >= MAX(1,M).
!>

LDX is INTEGER, the leading dimension of the array X, and the rule is LDX >= MAX(1,M). read it and weep, but like, affectionately 😭

K

!>          K is INTEGER array, dimension (M)
!>          On entry, K contains the permutation vector. K is used as
!>          internal workspace, but reset to its original value on
!>          output.
!>

K is an INTEGER array with dimension (M). on entry, K contains the permutation vector. lowkey the wild part: K gets used as internal workspace, but it's reset to its original value on output. she borrows your car, fills the tank, hands back the keys. main character energy fr fr 🔥

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🌈 Author 🌈

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

Definition at line 103 of file clapmr.f. yes, we're citing our sources, academic integrity is also slay 📚

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💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code. not a human, just a very diligent little robot doing her best 🧚

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ok gorl that's the whole page, no cliffhangers, every flag and caveat accounted for 💀

so yeah — that's SRC/clapmr.f from LAPACK, Version 3.12.0, dated SRC/clapmr.f(3) at the bottom of the original. go rearrange some rows, you absolute legend, and remember: LDX >= MAX(1,M) or it's on sight 🍓💖