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dla_gerpvgrw.f(3) LAPACK dla_gerpvgrw.f(3)

NAME

dla_gerpvgrw.f -

SYNOPSIS

Functions/Subroutines


double precision function dla_gerpvgrw (N, NCOLS, A, LDA, AF, LDAF)
 
DLA_GERPVGRW

Function/Subroutine Documentation

double precision function dla_gerpvgrw (integerN, integerNCOLS, double precision, dimension( lda, * )A, integerLDA, double precision, dimension( ldaf, * )AF, integerLDAF)

DLA_GERPVGRW
Purpose: 
 DLA_GERPVGRW computes the reciprocal pivot growth factor
 norm(A)/norm(U). The "max absolute element" 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:
N 
          N is INTEGER
     The number of linear equations, i.e., the order of the
     matrix A.  N >= 0.
NCOLS 
          NCOLS is INTEGER
     The number of columns of the matrix A. NCOLS >= 0.
A 
          A is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (LDAF,N)
     The factors L and U from the factorization
     A = P*L*U as computed by DGETRF.
LDAF 
          LDAF is INTEGER
     The leading dimension of the array AF.  LDAF >= max(1,N).
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 100 of file dla_gerpvgrw.f.

Author

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