.TH "sla_porpvgrw.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME sla_porpvgrw.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "real function \fBsla_porpvgrw\fP (UPLO, NCOLS, A, LDA, AF, LDAF, WORK)" .br .RI "\fI\fBSLA_PORPVGRW\fP computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "real function sla_porpvgrw (character*1UPLO, integerNCOLS, real, dimension( lda, * )A, integerLDA, real, dimension( ldaf, * )AF, integerLDAF, real, dimension( * )WORK)" .PP \fBSLA_PORPVGRW\fP computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix\&. .PP \fBPurpose: \fP .RS 4 .PP .nf SLA_PORPVGRW 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. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. .fi .PP .br \fINCOLS\fP .PP .nf NCOLS is INTEGER The number of columns of the matrix A. NCOLS >= 0. .fi .PP .br \fIA\fP .PP .nf A is REAL array, dimension (LDA,N) On entry, the N-by-N matrix A. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). .fi .PP .br \fIAF\fP .PP .nf 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. .fi .PP .br \fILDAF\fP .PP .nf LDAF is INTEGER The leading dimension of the array AF. LDAF >= max(1,N). .fi .PP .br \fIWORK\fP .PP .nf WORK is REAL array, dimension (2*N) .fi .PP .RE .PP \fBAuthor:\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 September 2012 .RE .PP .PP Definition at line 105 of file sla_porpvgrw\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.