SRC/zla_herpvgrw.f(3)

💖 NAME

Okay bestie, this is the SRC/zla_herpvgrw.f(3) page from the Library Functions Manual, and the function serving main-character energy is ZLA_HERPVGRW. 💅

✨ SYNOPSIS

Functions/Subroutines

• double precision function zla_herpvgrw (uplo, n, info, a, lda, af, ldaf, ipiv, work) — ZLA_HERPVGRW

🎀 Function/Subroutine Documentation

double precision function zla_herpvgrw (character*1 uplo, integer n, integer
       info, complex*16, dimension( lda, * ) a, integer lda, complex*16,
       dimension( ldaf, * ) af, integer ldaf, integer, dimension( * ) ipiv,
       double precision, dimension( * ) work)

ZLA_HERPVGRW

🔥 Purpose

Not me explaining the glow-up of this routine: ZLA_HERPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U). 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. This also means that the solution X, estimated condition numbers, and error bounds could be unreliable. 😭

🌸 Parameters

• UPLO — CHARACTER*1
  • = 'U': Upper triangle of A is stored;
  • = 'L': Lower triangle of A is stored.
• N — INTEGER. The number of linear equations, i.e., the order of the matrix A. N >= 0.
• INFO — INTEGER. The value of INFO returned from ZHETRF, .i.e., the pivot in column INFO is exactly 0.
• A — COMPLEX*16 array, dimension (LDA,N). On entry, the N-by-N matrix A.
• LDA — INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• AF — COMPLEX*16 array, dimension (LDAF,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHETRF.
• LDAF — INTEGER. The leading dimension of the array AF. LDAF >= max(1,N).
• IPIV — INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by ZHETRF.
• WORK — DOUBLE PRECISION array, dimension (2*N).

👑 Author

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

Definition at line 121 of file zla_herpvgrw.f.

💜 Author

Generated automatically by Doxygen for LAPACK from the source code.

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That’s the tea ☕. Cute sign-off time: this footer says LAPACK Version 3.12.0 and the source path is SRC/zla_herpvgrw.f(3); no date is shown on this footer, bestie. 💖✨