TESTING/LIN/dget02.f(3)

🎀 NAME 🎀

okay bestie, welcome to the Library Functions Manual page for TESTING/LIN/dget02.f — yes, the (3) page too, iykyk. This is where DGET02 lives, and it is lowkey iconic. 💅

✨ SYNOPSIS ✨

🛠️ Functions/Subroutines 🛠️

subroutine dget02 (trans, m, n, nrhs, a, lda, x, ldx, b, ldb, rwork, resid)

DGET02 — that’s the whole vibe. 💖

📚 Function/Subroutine Documentation 📚

subroutine dget02 (character trans, integer m, 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)

DGET02 — main character energy, fr fr. 🫶

🎯 Purpose 🎯

okay so DGET02 computes the residual for a solution of a system of linear equations op(A)*X = B:

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

where op(A) = A or A**T, depending on TRANS, and EPS is the machine epsilon.

The norm used is the 1-norm. periodt. 💖

🌈 Parameters 🌈

• TRANS — TRANS is CHARACTER*1. It specifies the form of the system of equations:
  • = 'N': A * X = B (No transpose)
  • = 'T': A**T * X = B (Transpose)
  • = 'C': A**H * X = B (Conjugate transpose = Transpose)
• M — M is INTEGER. The number of rows of the matrix A. M >= 0. 🫶
• N — N is INTEGER. The number of 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 M x N matrix A.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,M).
• 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. If TRANS = 'N', LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).
• 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 - op(A)*X.
• LDB — LDB is 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 — RWORK is DOUBLE PRECISION array, dimension (M). That’s it, no extra lore. 💀
• RESID — RESID is DOUBLE PRECISION. The maximum over the number of right hand sides of norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ).

👑 Author 👑

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

Definition at line 133 of file dget02.f. 🧾

🌸 Author 🌸

Generated automatically by Doxygen for LAPACK from the source code.

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okay that’s the whole page bestie 💖 — source/version: LAPACK Version 3.12.0; page: TESTING/LIN/dget02.f(3). bye and slay 🫶