ZPTT01(3)

ZPTT01(3) 🌸 — Library Functions Manual

okay bestie, this is the manual page for ZPTT01(3), and yes it lives in the Library Functions Manual. It's giving “I reconstruct tridiagonal matrices and check residuals” energy. 💅

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NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zptt01.f

That's the file path, bestie — no cap, that's the whole NAME section. 🫶

SYNOPSIS ✨

Functions/Subroutines

       subroutine ZPTT01 (n, d, e, df, ef, work, resid)
           ZPTT01

Function/Subroutine Documentation 🦋

Full signature, exactly as the source says it:

   subroutine ZPTT01 (integer n, double precision, dimension( * ) d,
       complex*16, dimension( * ) e, double precision, dimension( * ) df,
       complex*16, dimension( * ) ef, complex*16, dimension( * ) work, double
       precision resid)
       ZPTT01

Purpose 🎯

ZPTT01 reconstructs a tridiagonal matrix A from its L*D*L' factorization and computes the residual

norm(L*D*L' - A) / ( n * norm(A) * EPS ),

where EPS is the machine epsilon. That's the whole vibe: rebuild A, compare, get a residual. Periodt. 💅

Parameters 🌸

• N — N is INTEGER. The order of the matrix A.
• D — D is DOUBLE PRECISION array, dimension (N). The n diagonal elements of the tridiagonal matrix A.
• E — E is COMPLEX*16 array, dimension (N-1). The (n-1) subdiagonal elements of the tridiagonal matrix A.
• DF — DF is DOUBLE PRECISION array, dimension (N). The n diagonal elements of the factor L from the L*D*L' factorization of A.
• EF — EF is COMPLEX*16 array, dimension (N-1). The (n-1) subdiagonal elements of the factor L from the L*D*L' factorization of A.
• WORK — WORK is COMPLEX*16 array, dimension (2*N).
• RESID — RESID is DOUBLE PRECISION. norm(L*D*L' - A) / (n * norm(A) * EPS).

Author 🫶

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

Definition at line 91 of file zptt01.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 — and the footer's path is /home/abui...IN/zptt01.f(3). That's the whole footer vibe. Bye! 🌈