HPL_dlocswpN(3)

💖 HPL_dlocswpN 💖

okay so bestie, welcome to the HPL Library Functions corner of the man pages — this one's all about HPL_dlocswpN, which locally swaps rows within panel. that's the whole vibe. it's giving "small but mighty" ✨

---

🌸 NAME 🌸

HPL_dlocswpN — locally swaps rows within panel. yes queen, that's literally the entire job description and she does it flawlessly 💅

---

🎀 SYNOPSIS 🎀

#include "hpl.h"

void HPL_dlocswpN( HPL_T_panel * PANEL, const int II, const int JJ,
double * WORK );

copy that exactly, no cap 🫶

---

✨ DESCRIPTION ✨

so HPL_dlocswpN performs the local swapping operations within a panel. that's the mission. 🦋

here's the tea though: the lower triangular N0-by-N0 upper block of the panel is stored in no-transpose form — meaning it's just like the input matrix itself. no transposing, no games, we keep it as-is. iconic behavior honestly 👑

---

💜 ARGUMENTS 💜

• PANEL (local input/output) HPL_T_panel * — on entry, PANEL points to the data structure containing the panel information. she's the main character, she holds all the panel lore 📋
• II (local input) const int — on entry, II specifies the row offset where the column to be operated on starts, with respect to the panel. it's giving "where does the drama begin, row-wise" 🎯
• JJ (local input) const int — on entry, JJ specifies the column offset where the column to be operated on starts, with respect to the panel. same energy, but for columns 💫
• WORK (local workspace) double * — on entry, WORK is a workarray of size at least 2 * (4+2*N0). let's break down what's living inside her:
  • WORK[0] contains the local maximum absolute value scalar 🔥
  • WORK[1] contains the corresponding local row index
  • WORK[2] contains the corresponding global row index
  • WORK[3] is the coordinate of the process owning this max 🗺️
  • the N0 length max row is stored in WORK[4:4+N0-1] — and note that this is also the JJth row (or column) of L1 👀
  • the remaining part of this array is used as workspace 🛠️

ngl that's a lot of jobs for one array but she's handling it, periodt 💅

---

🦋 SEE ALSO 🦋

the whole friend group, fr fr — go say hi to:

• HPL_dlocmax (3)
• HPL_dlocswpT (3)
• HPL_pdmxswp (3)
• HPL_pdpancrN (3)
• HPL_pdpancrT (3)
• HPL_pdpanllN (3)
• HPL_pdpanllT (3)
• HPL_pdpanrlN (3)
• HPL_pdpanrlT (3)
• HPL_pdrpancrN (3)
• HPL_pdrpancrT (3)
• HPL_pdrpanllN (3)
• HPL_pdrpanllT (3)
• HPL_pdrpanrlN (3)
• HPL_pdrpanrlT (3)
• HPL_pdfact (3)

---

okay that's the whole page bestie, you ate that reading session 🍓 this was HPL 2.2, dated February 24, 2016 — shoutout to the HPL girlies who wrote her, she's been serving local row swaps since day one 💖✨🌈

xoxo, go compile something cute 🎀