SLA_PORPVGRW(3)

💅 SLA_PORPVGRW(3) 💅

okay bestie, welcome to the Library Functions Manual — this is the page for SLA_PORPVGRW, and it's literally about computing the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix. no cap 🫶

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✨ NAME ✨

This page is for this exact file, bestie:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/sla_porpvgrw.f

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🌸 SYNOPSIS 🌸

Functions/Subroutines

real function SLA_PORPVGRW (uplo, ncols, a, lda, af, ldaf, work)

SLA_PORPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix.

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🧚 Function/Subroutine Documentation 🧚

real function SLA_PORPVGRW (character*1 uplo, integer ncols, real,
    dimension( lda, * ) a, integer lda, real, dimension( ldaf, * ) af,
    integer ldaf, real, dimension( * ) work)

okay so SLA_PORPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix. that's the whole main character energy of this page 💅

🔥 Purpose 🔥

okay so SLA_PORPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U). the page literally says — double space and all — The norm is used. if this is much less than 1, the stability of the LU factorization of the (equilibrated) matrix A could be poor. that also means the solution X, estimated condition numbers, and error bounds could be unreliable. 💀

🎀 Parameters 🎀

• UPLO — UPLO is CHARACTER*1
  • = 'U': Upper triangle of A is stored;
  • = 'L': Lower triangle of A is stored.
• NCOLS — NCOLS is INTEGER
  • The number of columns of the matrix A. NCOLS >= 0.
• A — A is REAL array, dimension (LDA,N)
  • On entry, the N-by-N matrix A.
• LDA — LDA is INTEGER
  • The leading dimension of the array A. LDA >= max(1,N).
• AF — AF is REAL array, dimension (LDAF,N)
  • The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, as computed by SPOTRF.
• LDAF — LDAF is INTEGER
  • The leading dimension of the array AF. LDAF >= max(1,N).
• WORK — WORK is REAL array, dimension (2*N)

👑 Author 👑

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

Definition at line 103 of file sla_porpvgrw.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💋 cute sign-off time: the footer says LAPACK Version 3.12.0 and /home/abui..._porpvgrw.f(3) — bye bestie, slay your linear algebra 👑✨