TESTING/LIN/cppt02.f(3)

💖 NAME 💖

okay so this page is TESTING/LIN/cppt02.f(3), live from the Library Functions Manual, and it's all about the CPPT02 subroutine situation. bestie, we're in the linear algebra testing zone and it's giving very specific packed-storage energy. ✨

🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine cppt02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)
    CPPT02

🦋 Function/Subroutine Documentation 🦋

subroutine cppt02 (character uplo, integer n, integer nrhs, complex,
    dimension( * ) a, complex, dimension( ldx, * ) x, integer ldx, complex,
    dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real
    resid)
    CPPT02

Purpose

CPPT02 computes the residual in the solution of a Hermitian system of linear equations A*x = b when packed storage is used for the coefficient matrix. the ratio it computes is:

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

where EPS is the machine precision. periodt. 💅

Parameters

• UPLO — CHARACTER*1. specifies whether the upper or lower triangular part of the Hermitian matrix A is stored: = 'U': Upper triangular, = 'L': Lower triangular. simple as that, bestie. 🎀
• N — INTEGER. the number of rows and columns of the matrix A. N >= 0.
• NRHS — INTEGER. the number of columns of B, the matrix of right hand sides. NRHS >= 0.
• A — COMPLEX array, dimension (N*(N+1)/2). the original Hermitian matrix A, stored as a packed triangular matrix. packed and iconic. 🦋
• X — COMPLEX array, dimension (LDX,NRHS). the computed solution vectors for the system of linear equations.
• LDX — INTEGER. the leading dimension of the array X. LDX >= max(1,N).
• B — COMPLEX 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. so yeah, it gets replaced, no cap. 😭
• LDB — INTEGER. the leading dimension of the array B. LDB >= max(1,N).
• RWORK — REAL array, dimension (N).
• RESID — REAL. the maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ). this is the main-character output, lowkey. 👑

Author

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

📍 Definition at line 121 of file cppt02.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code. the robots really said "we got this" and honestly? slay. 🤖✨

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that's the whole page, bestie! this one is from LAPACK Version 3.12.0 and it's the TESTING/LIN/cppt02.f(3) page. stay hydrated, keep your residual low, and remember: packed storage is still storage. 💖🎀🦋