HPL_pdtest(3)

✨ HPL_pdtest — bestie's guide to running ONE (1) test ✨

okay so like. hi. you're here because you wanna know about HPL_pdtest from the HPL library functions, and honestly? valid. this one's a lil function that does a WHOLE lot of work and we're gonna break it down together, no cap 💅

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🌸 NAME 🌸

HPL_pdtest — Perform one test. that's it. that's the whole vibe. one test. iconic behavior honestly.

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🎀 SYNOPSIS 🎀

#include "hpl.h"

void HPL_pdtest( HPL_T_test * TEST, HPL_T_grid * GRID, HPL_T_palg *
ALGO, const int N, const int NB );

look at her. five args. serving real "trust the process" energy 🫶

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💖 DESCRIPTION 💖

okay so HPL_pdtest performs one test given a whole lil set of parameters — think the process grid, the problem size, the distribution blocking factor, the whole squad ✨

here's the pipeline, bestie, and it's giving main character energy from start to finish:

• it generates the data
• it calls and times the linear system solver
• it checks the accuracy of the obtained vector solution
• it writes all that info to the file pointed to by TEST->outfp

periodt. that's the whole job. she does data, she does timing, she does accuracy check, she does the receipts 💅

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👑 ARGUMENTS 👑

• TEST (global input) — HPL_T_test *

On entry, TEST points to a testing data structure, and she's carrying a LOT of lore, so listen up:

• outfp specifies the output file where the results will be printed. it's only defined and used by the process 0 of the grid — so like, process zero is the one holding the pen, everyone else is just vibing 🖊️
• thrsh specifies the threshhold value for the test ratio.

concretely, a test is declared "PASSED" if and only if this inequality is satisfied:

||Ax-b||_oo / ( epsil * ( || x ||_oo * || A ||_oo + || b ||_oo ) * N )  < thrsh

where epsil is the relative machine precision of the distributed computer. (math girlies rise up, this is your moment 🌈)

and finally, the test counters kfail, kpass, kskip and ktest get updated like so:

• if the test passes, kpass is incremented by one ✅
• if the test fails, kfail is incremented by one 💀
• if the test is skipped, kskip is incremented by one 🙈
• ktest is left unchanged. she's not like the other counters. she's chillin 😌

• GRID (local input) — HPL_T_grid *

On entry, GRID points to the data structure containing the process grid information. it's the map of who's where, basically 🗺️

• ALGO (global input) — HPL_T_palg *

On entry, ALGO points to the data structure containing the algorithmic parameters to be used for this test. all the little knobs and dials, bestie ⚙️

• N (global input) — const int

On entry, N specifies the order of the coefficient matrix A. and here's the rule: N must be at least zero. zero is fine. negative is NOT the vibe. 🚫

• NB (global input) — const int

On entry, NB specifies the blocking factor used to partition and distribute the matrix A. and heads up: NB must be larger than one. so 1 is a no, 0 is a no, negative is a big no. 2 and up, slay 🎀

fr fr though — those constraints on N and NB are not suggestions. N ≥ 0 and NB > 1. don't test the function's patience, she WILL be dramatic about it.

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🔥 SEE ALSO 🔥

• HPL_pddriver (3)
• HPL_pdinfo (3)

go read those too, they're the friend group, you can't just know one of them 😭

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and that's the whole page, bestie!! you understood it, you ate, no crumbs left 💅✨

this was HPL version 2.2, dated February 24, 2016 — so yeah she's a lil vintage but she still serves. mwah 🫶💖