TESTING/LIN/zpot06.f(3)

💅 TESTING/LIN/zpot06.f(3) 💅

okay so this is the Library Functions Manual page for TESTING/LIN/zpot06.f, and bestie, it’s giving “Fortran residual-checking subroutine that knows exactly what it’s doing.” We’re talking about zpot06 — yes, the same energy as ZPOT06 — and I’m gonna walk you through every flag, parameter, and tiny detail without dropping a single crumb. 🫶✨

✨ NAME ✨

TESTING/LIN/zpot06.f — that’s the file/page name, and the main character is the subroutine zpot06. No cap. 🎀

🦋 SYNOPSIS 🦋

🧚 Functions/Subroutines 🧚

• subroutine zpot06 (uplo, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid) — and the page literally labels it ZPOT06. Iconic.

subroutine zpot06 (uplo, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)

🌸 Function/Subroutine Documentation 🌸

Here’s the full signature in all its Fortran glory, exactly as written:

subroutine zpot06 (character uplo, integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldx, * ) x, integer ldx, complex*16, dimension( ldb, * ) b, integer ldb, double precision, dimension( * ) rwork, double precision resid)

ZPOT06

💖 Purpose 💖

okay so the purpose: ZPOT06 computes the residual for a solution of a system of linear equations A*x = b:

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

where EPS is the machine epsilon. That’s the whole vibe: it’s checking how close the computed solution is, mathematically speaking. 💅

🎀 Parameters 🎀

here’s the cast, one by one, no skips:

• UPLO — CHARACTER*1. Specifies whether the upper or lower triangular part of the symmetric 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 (LDA,N). The original M x N matrix A.
• LDA — INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• 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. If TRANS = 'N', LDX >= max(1,N); if TRANS = 'T' or 'C', 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. IF TRANS = 'N', LDB >= max(1,M); if TRANS = 'T' or 'C', 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 ).

👑 Author 👑

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

Definition at line 125 of file zpot06.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

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and that’s the page, bestie! 💖 source/version tea: LAPACK Version 3.12.0, page path TESTING/LIN/zpot06.f(3). The original footer didn’t hand me a date, so I’m not inventing one — just those exact receipts, periodt. 🌈🫶✨