ZPPT02(3)

💅 NAME

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zppt02.f — okay so this is the Library Functions Manual page for the ZPPT02 subroutine, bestie. It’s a LAPACK source-file page, and we’re about to get into residual math. Slay. ✨

🌸 SYNOPSIS

🫶 Functions/Subroutines

subroutine ZPPT02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)
    ZPPT02

🎀 Function/Subroutine Documentation

subroutine ZPPT02 (character uplo, integer n, integer nrhs, complex*16,
    dimension( * ) a, complex*16, dimension( ldx, * ) x, integer ldx,
    complex*16, dimension( ldb, * ) b, integer ldb, double precision,
    dimension( * ) rwork, double precision resid)
    ZPPT02

🎯 Purpose

ZPPT02 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 computed is:

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

where EPS is the machine precision. Literally the whole vibe of this subroutine, no cap. 💖

✨ 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
• 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*16 array, dimension (N*(N+1)/2). The original Hermitian matrix A, stored as a packed triangular matrix.
• X — COMPLEX*16 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*16 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.
• LDB — INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• RWORK — DOUBLE PRECISION array, dimension (N).
• RESID — DOUBLE PRECISION. The maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

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👑 Author

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

Definition at line 121 of file zppt02.f.

🤖 Author

Generated automatically by Doxygen for LAPACK from the source code.

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That’s the whole page, bestie! Footer source/version check: LAPACK, Version 3.12.0, source /home/abui...IN/zppt02.f(3). Bye icon! 💅🦋