HPL_dlaswp03T(3)

💖 HPL_dlaswp03T — bestie's guide to the HPL Library Functions 💖

okay so like. hi. you're here for HPL_dlaswp03T(3), which lives in the HPL Library Functions section, and honestly? it's a whole little icon. it copies columns of W into U. that's the vibe. that's the whole job. she's simple, she's efficient, she knows exactly what she's doing 💅

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✨ NAME ✨

HPL_dlaswp03T — copy columns of W into U.

no cap, that's literally it. main character behaviour: copy. columns. into U. periodt.

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🦋 SYNOPSIS 🦋

#include "hpl.h"

void HPL_dlaswp03T( const int M, const int N, double * U, const int LDU,
       const double * W0, const double * W, const int LDW );

okay so you #include "hpl.h" first (obviously, she needs her support system) and then you call her with all seven of those arguments. yes seven. she's high maintenance but she's worth it 🎀

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🌸 DESCRIPTION 🌸

so here's the tea: HPL_dlaswp03T copies columns of W into an array U. and where does it put them? the destination in U of these columns contained in W is stored within W0. like, W0 is the lil map that says "this column goes here, that column goes there" 🗺️✨

she's a courier. W0 is the address label. she delivers. no questions asked. iconic.

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👑 ARGUMENTS 👑

• M — (local input) const int — on entry, M specifies the number of columns of W stored contiguously that should be copied into U. M must be at least zero. yeah bestie, zero is fine, negative is not, we don't do that here 🙈
• N — (local input) const int — on entry, N specifies the length of columns of W stored contiguously that should be copied into U. N must be at least zero. same energy, same rule 💜
• U — (local input/output) double * — on entry, U points to an array of dimension (LDU,M). columns of W are copied within the array U at the positions specified in W0. she's both input and output btw, which is giving dual-threat energy 🔥
• LDU — (local input) const int — on entry, LDU specifies the leading dimension of the array U. LDU must be at least MAX(1,N). don't skimp on her, she needs room to breathe ✨
• 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. this is the little address book 📖 keep it accurate or things get weird.
• W — (local input) const double * — on entry, W is an array of size (LDW,M), that contains data to be copied into U. for i in [0..M), entries W(:,i) should be copied into the row or column W0(i*LDW) of U. okay so that's the whole formula right there, copy it down fr fr 📝
• 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). note the +1 bestie, she's not like LDU, she wants one extra 🍓

⚠️ friendly reminder: M ≥ 0, N ≥ 0, LDU ≥ MAX(1,N), LDW ≥ MAX(1,N+1). these aren't suggestions, they're the vibe check. fail them and it's giving undefined behaviour 💀

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🌈 SEE ALSO 🌈

the whole dlaswp cinematic universe, go off:

• 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).

(yes HPL_dlaswp03T (3) links to itself. she's self-referential. we love a confident queen 👑)

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and that's the page!! this lil masterpiece is from HPL 2.2, dated February 24, 2016 🎀 ty for reading bestie, now go copy some columns, you've got this 🫶✨💖