TESTING/LIN/dpot02.f(3)

🎀 NAME

TESTING/LIN/dpot02.f — bestie, that's the manual page name, and this whole page is the dpot02 lore. We're folding the manual name in right here so you know exactly what page you're on. 💅

✨ SYNOPSIS

Functions/Subroutines

subroutine dpot02 (uplo, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)

DPOT02

💅 Function/Subroutine Documentation

subroutine dpot02 (character uplo, integer n, integer nrhs, double
       precision, dimension( lda, * ) a, integer lda, double precision,
       dimension( ldx, * ) x, integer ldx, double precision, dimension( ldb, *
       ) b, integer ldb, double precision, dimension( * ) rwork, double
       precision resid)

DPOT02

🌟 Purpose

Okay so DPOT02 computes the residual for the solution of a symmetric system of linear equations A*x = b:

RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS ),

where EPS is the machine epsilon. Math girlie really said “measure the chaos,” and honestly? Iconic. ✨

🧚 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.
• NRHS — NRHS is INTEGER. The number of columns of B, the matrix of right hand sides. NRHS >= 0.
• A — A is DOUBLE PRECISION array, dimension (LDA,N). The original symmetric matrix A.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• X — X is DOUBLE PRECISION array, dimension (LDX,NRHS). The computed solution vectors for the system of linear equations.
• LDX — LDX is INTEGER. The leading dimension of the array X. LDX >= max(1,N).
• B — B is DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, the right hand side vectors for the system of linear equations. On exit, B is overwritten with the difference B - A*X. Not me getting emotionally attached to a workspace array 😭
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• RWORK — RWORK is DOUBLE PRECISION array, dimension (N).
• RESID — RESID is DOUBLE PRECISION. The maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

👑 Author

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

Definition at line 125 of file dpot02.f.

---

This cutie was generated automatically by Doxygen for LAPACK from the source code — and the footer tea is: LAPACK Version 3.12.0, manual page TESTING/LIN/dpot02.f(3). Bye bestie, go slay those residuals! 💖✨