DPTT02(3)

💅 DPTT02(3) — Library Functions Manual ✨

okay so bestie, the manual name is Library Functions Manual, the page is DPTT02(3), and the file vibe is dptt02.f(3). The way this page is literally giving residual main character energy, and we’re gonna keep every single detail exactly as it appears. no cap, fr fr. 🫶

📛 NAME

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dptt02.f

🌀 SYNOPSIS

📚 Functions/Subroutines

       subroutine DPTT02 (n, nrhs, d, e, x, ldx, b, ldb, resid)
           DPTT02

🧚 Function/Subroutine Documentation

   subroutine DPTT02 (integer n, integer nrhs, double precision, dimension( * )
       d, double precision, dimension( * ) e, double precision, dimension( ldx,
       * ) x, integer ldx, double precision, dimension( ldb, * ) b, integer
       ldb, double precision resid)
       DPTT02

🎀 Purpose

DPTT02 computes the residual for the solution to a symmetric tridiagonal system of equations:

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

where EPS is the machine epsilon. obsessed. ✨

🌸 Parameters

Vibe check: every parameter below is real and must stay exactly as written.

• N — N is INTEGER. The order of the matrix A.
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0.
• D — D is DOUBLE PRECISION array, dimension (N). The n diagonal elements of the tridiagonal matrix A.
• E — E is DOUBLE PRECISION array, dimension (N-1). The (n-1) subdiagonal elements of the tridiagonal matrix A.
• X — X is DOUBLE PRECISION array, dimension (LDX,NRHS). The n by nrhs matrix of solution vectors X.
• LDX — LDX is INTEGER. The leading dimension of the array X. LDX >= max(1,N).
• B — B is DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, the n by nrhs matrix of right hand side vectors B. On exit, B is overwritten with the difference B - A*X.
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• RESID — RESID is DOUBLE PRECISION. 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 103 of file dptt02.f.

📝 Author

Generated automatically by Doxygen for LAPACK from the source code.

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