TESTING/LIN/zget02.f(3)

okay bestie, welcome to the TESTING/LIN/zget02.f(3) page from the Library Functions Manual — it's giving LAPACK testing energy, and we're about to read exactly one subroutine's whole deal 💅✨

💖 NAME 💖

TESTING/LIN/zget02.f — that's the file/page name, no cap. The subroutine inside is ZGET02, and she's here to check residuals 🫶

🌸 SYNOPSIS 🌸

🧚 Functions/Subroutines 🧚

       subroutine zget02 (trans, m, n, nrhs, a, lda, x, ldx, b, ldb, rwork,
           resid)

Lowkey just one entry: ZGET02 💫

🦋 Function/Subroutine Documentation 🦋

   subroutine zget02 (character trans, integer m, 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)

ZGET02 ✨

🎯 Purpose 🎯

okay so ZGET02 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, A**T, or A**H, depending on TRANS, and EPS is the machine epsilon. Periodt. 🔥

🌈 Parameters 🌈

• TRANS — TRANS is CHARACTER*1. 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)
• 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 COMPLEX*16 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 COMPLEX*16 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 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 - op(A)*X.
• LDB — LDB is INTEGER. The leading dimension of the array B. The original says IF TRANS = 'N', LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).
• RWORK — RWORK is DOUBLE PRECISION array, dimension (M).
• 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 132 of file zget02.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that's the whole page 💖. Cute footer sign-off: LAPACK Version 3.12.0, page TESTING/LIN/zget02.f(3) — that's the source/version line, and the footer doesn't print a date, so we're not inventing one 💅✨