TESTING/LIN/dppt03.f(3)

💅 TESTING/LIN/dppt03.f 💅

okay bestie, welcome to the LAPACK manual page for TESTING/LIN/dppt03.f(3) — manual name folded in right here at the top, main character energy only, no copied header line. This whole page is about DPPT03 and its residual-checking moment. 🎀✨

🌸 NAME 🌸

TESTING/LIN/dppt03.f

✨ SYNOPSIS ✨

💖 Functions/Subroutines 💖

• subroutine dppt03 (uplo, n, a, ainv, work, ldwork, rwork, rcond, resid) — the whole call, right up front. DPPT03 is the function/subroutine doing the thing. 💅

👑 Function/Subroutine Documentation 👑

here’s the full signature, no cap:

subroutine dppt03 (character uplo, integer n, double precision, dimension( *
) a, double precision, dimension( * ) ainv, double precision, dimension(
ldwork, * ) work, integer ldwork, double precision, dimension( * )
rwork, double precision rcond, double precision resid)

DPPT03 💖

🎀 Purpose 🎀

DPPT03 computes the residual for a symmetric packed matrix times its inverse:

norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * EPS ),

where EPS is the machine epsilon. slay, that’s the whole purpose. ✨

🌈 Parameters 🌈

• UPLO — UPLO is CHARACTER*1. It specifies whether the upper or lower triangular part of the symmetric matrix A is stored:
  • = 'U': Upper triangular
  • = 'L': Lower triangular
• N — N is INTEGER. The number of rows and columns of the matrix A. N >= 0.
• A — A is DOUBLE PRECISION array, dimension (N*(N+1)/2). The original symmetric matrix A, stored as a packed triangular matrix.
• AINV — AINV is DOUBLE PRECISION array, dimension (N*(N+1)/2). The (symmetric) inverse of the matrix A, stored as a packed triangular matrix.
• WORK — WORK is DOUBLE PRECISION array, dimension (LDWORK,N).
• LDWORK — LDWORK is INTEGER. The leading dimension of the array WORK. LDWORK >= max(1,N).
• RWORK — RWORK is DOUBLE PRECISION array, dimension (N).
• RCOND — RCOND is DOUBLE PRECISION. The reciprocal of the condition number of A, computed as ( 1/norm(A) ) / norm(AINV).
• RESID — RESID is DOUBLE PRECISION. norm(I - A*AINV) / ( N * norm(A) * norm(AINV) * EPS ).

💜 Author 💜

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

Definition at line 108 of file dppt03.f.

🌟 Author 🌟

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that’s the whole page. This is from the LAPACK manual, LAPACK Version 3.12.0, and the footer doesn’t show a separate date on this one — just the version and the page name TESTING/LIN/dppt03.f(3). stay slay, and may your residual always be tiny. 💖✨🎀