SRC/dlat2s.f(3)

📦
version 3.12.1 · 5 versions
, in arch rolling

Okay bestie, this page is literally from the LAPACK Library Functions Manual, and it’s all about one tiny-but-important conversion helper. Let’s get into it. 💅✨

🌸 NAME 🌸

SRC/dlat2s.f — that’s the filename in the NAME block, and honestly the page is serving exactly that. 🎀

💖 SYNOPSIS 💖

🧚 Functions/Subroutines

subroutine dlat2s (uplo, n, a, lda, sa, ldsa, info)
    DLAT2S converts a double-precision triangular matrix to a single-
    precision triangular matrix.

One subroutine, seven arguments, full conversion business. Slay. 💅

🦋 Function/Subroutine Documentation 🦋

subroutine dlat2s (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, real, dimension( ldsa, * ) sa, integer ldsa, integer info)

DLAT2S converts a double-precision triangular matrix to a single-precision triangular matrix.

🔥 Purpose

Okay so the purpose block says DLAT2S converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE PRECISION triangular matrix, A. That’s what the page says, bestie — I’m not editing the lore. 👑😭

RMAX is the overflow for the SINGLE PRECISION arithmetic. DLAS2S checks that all the entries of A are between -RMAX and RMAX. If not, the conversion is aborted and a flag is raised. 🚩

Also, this is an auxiliary routine, so there is no argument checking. Not even a little vibe check for the args. 🙈

🎀 Parameters 🎀

  • UPLO — CHARACTER*1. It tells you the triangle situation: = 'U': A is upper triangular; and = 'L': A is lower triangular.
  • N — INTEGER. The number of rows and columns of the matrix A. N >= 0.
  • A — DOUBLE PRECISION array, dimension (LDA,N). On entry, the N-by-N triangular coefficient matrix A.
  • LDA — INTEGER. The leading dimension of the array A. LDA >= max(1,N).
  • SA — REAL array, dimension (LDSA,N). Only the UPLO part of SA is referenced. On exit, if INFO=0, the N-by-N coefficient matrix SA; if INFO>0, the content of the UPLO part of SA is unspecified.
  • LDSA — INTEGER. The leading dimension of the array SA. LDSA >= max(1,M). Yes, the page says M here — I’m just reading it to you, bestie. 🙈
  • INFO — INTEGER. = 0: successful exit. = 1: an entry of the matrix A is greater than the SINGLE PRECISION overflow threshold; in this case, the content of the UPLO part of SA on exit is unspecified. 💀

👑 Author

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

Definition at line 110 of file dlat2s.f. 📍

👑 Author

Generated automatically by Doxygen for LAPACK from the source code. 🤖✨

Catch you later, bestie — this one is from LAPACK Version 3.12.0, page SRC/dlat2s.f(3). The footer doesn’t give a date, so I’m not inventing one. 🎀✨💖

📦 where this page comes from