SRC/dsyconv.f(3)

okay bestie, this page is from the Library Functions Manual and it’s all about SRC/dsyconv.f(3) 💅✨

💖 NAME 💖

SRC/dsyconv.f

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

• subroutine dsyconv (uplo, way, n, a, lda, ipiv, e, info) — DSYCONV

🦋 Function/Subroutine Documentation 🦋

subroutine dsyconv (character uplo, character way, integer n, double
    precision, dimension( lda, * ) a, integer lda, integer, dimension( * )
    ipiv, double precision, dimension( * ) e, integer info)

DSYCONV

🌸 Purpose: 🌸

DSYCONV converts A given by TRF into L and D, and vice-versa. It grabs the Non-diag elements of D (returned in workspace) and applies or reverses the permutation done in TRF. 🫶

💖 Parameters 💖

UPLO — CHARACTER*1. Tells you whether the details of the factorization are stored as an upper or lower triangular matrix, bestie:

• = 'U': Upper triangular, form is A = U*D*U**T;
• = 'L': Lower triangular, form is A = L*D*L**T.

WAY — CHARACTER*1:

• = 'C': Convert
• = 'R': Revert

N — INTEGER. The order of the matrix A. N >= 0. 🎀

A — DOUBLE PRECISION array, dimension (LDA,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF. 💅

LDA — INTEGER. The leading dimension of the array A. LDA >= max(1,N). 🌸

IPIV — INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by DSYTRF. 🦋

E — DOUBLE PRECISION array, dimension (N). E stores the supdiagonal/subdiagonal of the symmetric 1-by-1 or 2-by-2 block diagonal matrix D in LDLT. 🍓

INFO — INTEGER:

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value

🫶 Author 🫶

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

Definition at line 113 of file dsyconv.f.

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code.

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💖 Sign-off time, bestie: source/version info is LAPACK Version 3.12.0, and the page is SRC/dsyconv.f(3) — no separate calendar date shown in the footer, so I’m not inventing one 🙈💅🎀