SLATB4(3)

💅 SLATB4(3) — bestie's guide to the LAPACK matrix-vibe setter ✨

Okay so real talk, this page lives in the Library Functions Manual and it's all about the file /home/abui...IN/slatb4.f(3) — that's the whole address, yes it's long, no we're not shortening it, iykyk 🫶. Grab a snack and let's get into it.

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🌸 SYNOPSIS 🌸

Functions/Subroutines 💫

• subroutine SLATB4 (path, imat, m, n, type, kl, ku, anorm, mode, cndnum, dist) — the whole cast list, and yes that trailing dist is doing main character energy at the very end 💅
• SLATB4 — that's it, that's the name, slay

🦋 Function/Subroutine Documentation 🦋

Here's the full glow-up of the signature, character for character, no edits no cap:

subroutine SLATB4 (character*3 path, integer imat, integer m, integer n,
    character type, integer kl, integer ku, real anorm, integer mode, real
    cndnum, character dist)

And again, shorter, iconic:

SLATB4

✨ Purpose ✨

!> !> SLATB4 sets parameters for the matrix generator based on the type of !> matrix to be generated. !>

So like — it's the little subroutine that literally decides the vibes of the matrix you're about to generate. Type goes in, parameters come out. It's giving matchmaker but for matrices, and honestly? obsessed. 🔥

🎀 Parameters 🎀

Every single one, in order, nothing skipped, we don't do that here:

• PATH — !> PATH is CHARACTER*3, !> the LAPACK path name. 🛤️ Three characters of pure identity.
• IMAT — !> IMAT is INTEGER, !> an integer key describing which matrix to generate for this PATH. Think of it as the menu number at your fave restaurant, except the meal is a matrix 🍓
• M — !> M is INTEGER, !> the number of rows in the matrix to be generated. Rows. The horizontal girlies.
• N — !> N is INTEGER, !> the number of columns in the matrix to be generated. Columns. The vertical girlies. 🌈
• TYPE — !> TYPE is CHARACTER*1, !> the type of the matrix to be generated:
  • = 'S': symmetric matrix 🔁
  • = 'P': symmetric positive (semi)definite matrix 💖
  • = 'N': nonsymmetric matrix 🙈
• KL — !> KL is INTEGER, !> the lower band width of the matrix to be generated. Lowkey the lower bound, literally.
• KU — !> KU is INTEGER, !> the upper band width of the matrix to be generated. Highkey the upper bound, literally. ⬆️
• ANORM — !> ANORM is REAL, !> the desired norm of the matrix to be generated. The diagonal matrix of singular values or eigenvalues is scaled by this value. So it's not just a number, it's the number that scales the whole diagonal situation 👑
• MODE — !> MODE is INTEGER, !> a key indicating how to choose the vector of eigenvalues. A key! Another key! This subroutine is basically a keychain 🔑
• CNDNUM — !> CNDNUM is REAL, !> the desired condition number. Manifesting a good condition number for u ✨
• DIST — !> DIST is CHARACTER*1, !> the type of distribution to be used by the random number generator. Randomness, but make it typed 💫

🌟 Author 🌟

The absolute legends behind this:

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

A whole squad. Group project but they actually carried it 🫶👑

🔍 Definition 🔍

Defined at line 118 of file slatb4.f. Line 118! Not 117, not 119. Precision, periodt. 💅

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⭐ Author ⭐

This page was generated automatically by Doxygen for LAPACK from the source code. Robot-made, but make it cute 🤖🎀

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And that's the whole thing bestie, hope it slayed 💖 — this page is from LAPACK, Version 3.12.0, and it points at /home/abui...IN/slatb4.f(3). Bye!! 🌸🦋💜