HPL_dlaswp04T(3)

💖 HPL_dlaswp04T(3) — the HPL Library Functions glow-up 💖

okay bestie, sit down, hydrate, because we're about to talk about HPL_dlaswp04T from the HPL Library Functions and she is lowkey doing the most. what she does: copies columns of U into rows of A and then replaces those columns of U with columns of W. and as if that wasn't enough, M1 - M0 columns of W also get copied into U. she's giving multitasking icon behavior fr fr 🎀

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✨ NAME ✨

HPL_dlaswp04T — copy columns of U in rows of A and replace them with columns of W.

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🌸 SYNOPSIS 🌸

#include "hpl.h"

void HPL_dlaswp04T( const int M0, const int M1, const int N, double * U,
const int LDU, double * A, const int LDA, const double * W0, const
double * W, const int LDW, const int * LINDXA, const int * LINDXAU );

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🦋 DESCRIPTION 🦋

okay so here's the tea, and it's actually kind of a lot so stay with me 💜

HPL_dlaswp04T copies M0 columns of U into rows of A, and then replaces those very columns of U with columns of W. not done yet. in addition, M1 - M0 columns of W are copied into U. she's swapping, she's replacing, she's copying — she is the moment, no cap 👑

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💅 ARGUMENTS 💅

• M0 — (local input) const int — on entry, M0 specifies the number of columns of U that should be copied into A and replaced by columns of W. M0 must be at least zero. zero is fine, negative is NOT the vibe 🙈
• M1 — (local input) const int — on entry, M1 specifies the number of columnns of W that will be copied into U. M1 must be at least zero. (yes the original says "columnns", we love a typo that ate and left no crumbs 💀)
• N — (local input) const int — on entry, N specifies the length of the columns of U that will be copied into rows of A. N must be at least zero.
• U — (local input/output) double * — on entry, U points to an array of dimension (LDU,*). this array contains the columns that are to be copied into rows of A. she's both a source AND a destination, main character energy honestly ✨
• LDU — (local input) const int — on entry, LDU specifies the leading dimension of the array U. LDU must be at least MAX(1,N).
• A — (local output) double * — on entry, A points to an array of dimension (LDA,N). on exit, the rows of this array specified by LINDXA are replaced by columns of U indicated by LINDXAU. she comes in plain and leaves iconic 🌈
• LDA — (local input) const int — on entry, LDA specifies the leading dimension of the array A. LDA must be at least MAX(1,M0).
• W0 — (local input) const double * — on entry, W0 is an array of size (M-1)*LDW+1, that contains the destination offset in U where the columns of W should be copied.
• W — (local input) const double * — on entry, W is an array of size (LDW,M0+M1), that contains data to be copied into U. for i in [M0..M0+M1), the entries W(:,i) are copied into the column W0(i*LDW) of U.
• LDW — (local input) const int — on entry, LDW specifies the leading dimension of the array W. LDW must be at least MAX(1,N+1).
• LINDXA — (local input) const int * — on entry, LINDXA is an array of dimension M0 containing the local row indexes A into which columns of U are copied.
• LINDXAU — (local input) const int * — on entry, LINDXAU is an array of dimension M0 that contains the local column indexes of U that should be copied into A and replaced by the columns of W.

bestie pls respect those must be at least clauses. the constraints are the constraints, she's not being dramatic, she's being correct 🫶

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👑 SEE ALSO 👑

the whole dlaswp cinematic universe, go stan all of them:

• HPL_dlaswp00N (3)
• HPL_dlaswp10N (3)
• HPL_dlaswp01N (3)
• HPL_dlaswp01T (3)
• HPL_dlaswp02N (3)
• HPL_dlaswp03N (3)
• HPL_dlaswp03T (3)
• HPL_dlaswp04N (3)
• HPL_dlaswp04T (3)
• HPL_dlaswp05N (3)
• HPL_dlaswp05T (3)
• HPL_dlaswp06N (3)
• HPL_dlaswp06T (3)

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that's the whole page bestie, you ate it, you understood it, you're literally a linear algebra girlie now 💖

this has been HPL 2.2, dated February 24, 2016 — mwah, sending you a kiss, go compile something cute 🎀✨