TESTING/LIN/spot01.f(3)

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version 3.12.1 · 3 versions
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💖 NAME 💖

TESTING/LIN/spot01.f — okay so that's literally the name, bestie, and this whole page comes from the Library Functions Manual. It's giving "test routine main character energy" and we're obsessed.

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

  • subroutine spot01 (uplo, n, a, lda, afac, ldafac, rwork, resid) — SPOT01

🎀 Function/Subroutine Documentation 🎀

subroutine spot01 (character uplo, integer n, real, dimension( lda, * ) a,
    integer lda, real, dimension( ldafac, * ) afac, integer ldafac, real,
    dimension( * ) rwork, real resid)

SPOT01

🌸 Purpose 🌸

Okay so here's the vibe: SPOT01 reconstructs a symmetric positive definite matrix A from its L*L' or U'*U factorization, and then it computes the residual:

norm( L*L' - A ) / ( N * norm(A) * EPS ) or
norm( U'*U - A ) / ( N * norm(A) * EPS ),

where EPS is the machine epsilon. No cap, that's the whole purpose, and it ate. 💅

🧚 Parameters 🧚

  • UPLO is CHARACTER*1 — specifies whether the upper or lower triangular part of the symmetric matrix A is stored:
    • = 'U': Upper triangular
    • = 'L': Lower triangular
  • N is INTEGER — the number of rows and columns of the matrix A. N >= 0.
  • A is REAL array, dimension (LDA,N) — the original symmetric matrix A.
  • LDA is INTEGER — the leading dimension of the array A. LDA >= max(1,N)
  • AFAC is REAL array, dimension (LDAFAC,N) — on entry, the factor L or U from the L * L**T or U**T * U factorization of A. Overwritten with the reconstructed matrix, and then with the difference L * L**T - A (or U**T * U - A).
  • LDAFAC is INTEGER — the leading dimension of the array AFAC. LDAFAC >= max(1,N).
  • RWORK is REAL array, dimension (N)
  • RESID is REAL
    • If UPLO = 'L', norm(L * L**T - A) / ( N * norm(A) * EPS )
    • If UPLO = 'U', norm(U**T * U - A) / ( N * norm(A) * EPS )

👑 Author 👑

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

Definition at line 103 of file spot01.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

💖 That's the whole page, bestie — LAPACK Version 3.12.0, page TESTING/LIN/spot01.f(3), and that's a wrap! Slay and bye! 💖

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