ZUNT01(3)

📦 version 3.12.0, in opensuse-leap 16.0

💅 ZUNT01(3) — Library Functions Manual 💅

okay so bestie, this is the <pink>zunt01.f(3)</pink> page from the <purple>Library Functions Manual</purple>, and it's giving pure LAPACK documentation realness. Let's get into it. 🦋

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/zunt01.f

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine ZUNT01 (rowcol, m, n, u, ldu, work, lwork, rwork, resid)
    ZUNT01

🎀 Function/Subroutine Documentation 🎀

📜 subroutine ZUNT01 📜

subroutine ZUNT01 (character rowcol, integer m, integer n, complex*16, dimension( ldu, * ) u, integer ldu, complex*16, dimension( * ) work, integer lwork, double precision, dimension( * ) rwork, double precision resid)
    ZUNT01

🎯 Purpose 🎯

ZUNT01 checks that the matrix U is unitary by computing the ratio:

RESID = norm( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R',
or
RESID = norm( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'.

Alternatively, if there isn't sufficient workspace to form I - U*U' or I - U'*U, the ratio is computed as:

RESID = abs( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R',
or
RESID = abs( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'.

where EPS is the machine precision. ROWCOL is used only if m = n; if m > n, ROWCOL is assumed to be 'C', and if m < n, ROWCOL is assumed to be 'R'.

bestie, that last bit is important: the row/column choice only matters when m = n, and otherwise it gets auto-assumed based on which dimension is bigger. 💅

💖 Parameters 💖

  • ROWCOL — ROWCOL is CHARACTER. Specifies whether the rows or columns of U should be checked for orthogonality. Used only if M = N. = 'R': Check for orthogonal rows of U; = 'C': Check for orthogonal columns of U.
  • M — M is INTEGER. The number of rows of the matrix U.
  • N — N is INTEGER. The number of columns of the matrix U.
  • U — U is COMPLEX*16 array, dimension (LDU,N). The unitary matrix U. U is checked for orthogonal columns if m > n or if m = n and ROWCOL = 'C'. U is checked for orthogonal rows if m < n or if m = n and ROWCOL = 'R'.
  • LDU — LDU is INTEGER. The leading dimension of the array U. LDU >= max(1,M).
  • WORK — WORK is COMPLEX*16 array, dimension (LWORK).
  • LWORK — LWORK is INTEGER. The length of the array WORK. For best performance, LWORK should be at least N*N if ROWCOL = 'C' or M*M if ROWCOL = 'R', but the test will be done even if LWORK is 0.
  • RWORK — RWORK is DOUBLE PRECISION array, dimension (min(M,N)). Used only if LWORK is large enough to use the Level 3 BLAS code.
  • RESID — RESID is DOUBLE PRECISION. RESID = norm( I - U * U' ) / ( n * EPS ), if ROWCOL = 'R', or RESID = norm( I - U' * U ) / ( m * EPS ), if ROWCOL = 'C'.

👑 Author 👑

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

Definition at line 124 of file zunt01.f.

📝 Author 📝

Generated automatically by Doxygen for LAPACK from the source code.

okay that's the whole page, bestie 💖 — the footer vibe is LAPACK Version 3.12.0, source path /home/abui...IG/zunt01.f(3), and there's no explicit date listed. slay, you're done. 🎀

📦 where this page comes from