DSPMV(3)

💅 DSPMV(3) 💅

okay bestie, welcome to a page from the Library Functions Manual — and it's giving symmetric-matrix-in-packed-form realness. This is the glow-up of the DSPMV file, located at the path below, and yes we are keeping every little detail. periodt.

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/dspmv.f

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine DSPMV (uplo, n, alpha, ap, x, incx, beta, y, incy)
    DSPMV

🦋 Function/Subroutine Documentation 🦋

subroutine DSPMV (character uplo, integer n, double precision alpha, double
    precision, dimension(*) ap, double precision, dimension(*) x, integer
    incx, double precision beta, double precision, dimension(*) y, integer
    incy)

DSPMV

🎀 Purpose: 🎀

okay so DSPMV performs the matrix-vector operation

y := alpha*A*x + beta*y,

where alpha and beta are scalars, x and y are n element vectors and A is an n by n symmetric matrix, supplied in packed form. slay.

💖 Parameters 💖

• 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 — INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero.
• ALPHA — DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha.
• AP — DOUBLE PRECISION 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. 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.
• X — DOUBLE PRECISION array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the n element vector x.
• INCX — INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero.
• BETA — DOUBLE PRECISION. On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input.
• Y — DOUBLE PRECISION array, dimension at least ( 1 + ( n - 1 )*abs( INCY ) ). Before entry, the incremented array Y must contain the n element vector y. On exit, Y is overwritten by the updated vector y.
• INCY — INTEGER. On entry, INCY specifies the increment for the elements of Y. INCY must not be zero.

👑 Author 👑

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

🌈 Further Details: 🌈

Level 2 Blas routine. The vector and matrix arguments are not referenced when N = 0, or M = 0.

• -- 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 146 of file dspmv.f.

Author 💫 (Doxygen-generated note)

Generated automatically by Doxygen for LAPACK from the source code.

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bestie that's the whole page 🫶 the footer vibes are LAPACK, Version 3.12.0, and /home/abui...SRC/dspmv.f(3) — no cap, that's the source/version wrap-up. mwah 💋✨