CGTT02(3)

🎀 NAME

CGTT02 — this is the LAPACK Library Functions Manual page for /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/cgtt02.f. The header path vibe is /home/abui...IN/cgtt02.f(3) — yes bestie, the whole name section is literally that source file path, no extra lore. 💅

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine CGTT02 (trans, n, nrhs, dl, d, du, x, ldx, b, ldb, resid)

CGTT02

🦋 Function/Subroutine Documentation 🦋

subroutine CGTT02 (character trans, integer n, integer nrhs, complex,
    dimension( * ) dl, complex, dimension( * ) d, complex, dimension( * )
    du, complex, dimension( ldx, * ) x, integer ldx, complex, dimension(
    ldb, * ) b, integer ldb, real resid)

CGTT02

Purpose

Okay so CGTT02 computes the residual for the solution to a tridiagonal system of equations:

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

where EPS is the machine epsilon. That's the whole purpose, and it ate. 💖

Parameters

• TRANS — TRANS is CHARACTER. Specifies the form of the residual.
  • = 'N': B - A * X (No transpose)
  • = 'T': B - A**T * X (Transpose)
  • = 'C': B - A**H * X (Conjugate transpose)
• N — N is INTEGER. The order of the matrix A. N >= 0.
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0.
• DL — DL is COMPLEX array, dimension (N-1). The (n-1) sub-diagonal elements of A.
• D — D is COMPLEX array, dimension (N). The diagonal elements of A.
• DU — DU is COMPLEX array, dimension (N-1). The (n-1) super-diagonal elements of A.
• X — X is COMPLEX array, dimension (LDX,NRHS). The computed solution vectors X.
• LDX — LDX is INTEGER. The leading dimension of the array X. LDX >= max(1,N).
• B — B is 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 - op(A)*X.
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• RESID — RESID is REAL. 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 122 of file cgtt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

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That's the whole page, bestie 💖. The footer source/version energy is LAPACK Version 3.12.0, with the footer path /home/abui...IN/cgtt02.f(3) — no extra date on this one, just that version + source path. Slay, and remember: tridiagonal residuals are iconic. 🎀✨