/home/abui...SRC/sspr.f(3)

okay bestie, welcome to the Library Functions Manual page for /home/abui...SRC/sspr.f(3) — yes, that’s the page-header path, and the vibe is very matrix math. 💅

💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/sspr.f — that’s the file, fr fr. It’s the SSPR routine, and we’re gonna treat it like the main character it is. 👑

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

subroutine SSPR (uplo, n, alpha, x, incx, ap)
    SSPR

✨ Function/Subroutine Documentation ✨

Here’s the full signature, exactly as written:

subroutine SSPR (character uplo, integer n, real alpha, real, dimension(*) x, integer incx, real, dimension(*) ap)

SSPR

🎀 Purpose 🎀

SSPR performs the symmetric rank 1 operation

A := alpha*x*x**T + A,

where alpha is a real scalar, x is an n element vector and A is an n by n symmetric matrix, supplied in packed form. That’s the whole purpose, no cap.

🌸 Parameters 🌸

Okay bestie, parameter-by-parameter, and yes every single detail is staying. 🫶

UPLO

• UPLO — CHARACTER*1. On entry, UPLO specifies whether the upper or lower triangular part of the matrix A is supplied in the packed array AP as follows:
  • UPLO = 'U' or 'u' — the upper triangular part of A is supplied in AP.
  • UPLO = 'L' or 'l' — the lower triangular part of A is supplied in AP.

N

• N — INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero.

ALPHA

• ALPHA — REAL. On entry, ALPHA specifies the scalar alpha.

X

• X — REAL array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the n element vector x.

INCX

• INCX — INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Like, do not pass zero here — the page says must not be zero, periodt.

AP

• AP — REAL array, dimension at least ( ( n*( n + 1 ) )/2 ). Before entry with UPLO = 'U' or 'u', the array AP must contain the upper triangular part of the symmetric matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively, and so on. On exit, the array AP is overwritten by the upper triangular part of the updated matrix. Before entry with UPLO = 'L' or 'l', the array AP must contain the lower triangular part of the symmetric matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on. On exit, the array AP is overwritten by the lower triangular part of the updated matrix. That’s the packed-storage tea. 💅

👑 Author 👑

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

🧚 Further Details 🧚

• Level 2 Blas routine. iconic.
• -- Written on 22-October-1986.
• Jack Dongarra, Argonne National Lab.
• Jeremy Du Croz, Nag Central Office.
• Sven Hammarling, Nag Central Office.
• Richard Hanson, Sandia National Labs.

Definition at line 126 of file sspr.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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💖 That’s the whole page, bestie: LAPACK Version 3.12.0, source file sspr.f, page /home/abui...SRC/sspr.f(3), and the only date the page gives us is 22-October-1986. slay, signed off, no cap. 🎀🦋✨