.TH "cla_gbrpvgrw.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME cla_gbrpvgrw.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "real function \fBcla_gbrpvgrw\fP (N, KL, KU, NCOLS, AB, LDAB, AFB, LDAFB)" .br .RI "\fI\fBCLA_GBRPVGRW\fP computes the reciprocal pivot growth factor norm(A)/norm(U) for a general banded matrix\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "real function cla_gbrpvgrw (integerN, integerKL, integerKU, integerNCOLS, complex, dimension( ldab, * )AB, integerLDAB, complex, dimension( ldafb, * )AFB, integerLDAFB)" .PP \fBCLA_GBRPVGRW\fP computes the reciprocal pivot growth factor norm(A)/norm(U) for a general banded matrix\&. .PP \fBPurpose: \fP .RS 4 .PP .nf CLA_GBRPVGRW 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 \fIN\fP .PP .nf N is INTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0. .fi .PP .br \fIKL\fP .PP .nf KL is INTEGER The number of subdiagonals within the band of A. KL >= 0. .fi .PP .br \fIKU\fP .PP .nf KU is INTEGER The number of superdiagonals within the band of A. KU >= 0. .fi .PP .br \fINCOLS\fP .PP .nf NCOLS is INTEGER The number of columns of the matrix A. NCOLS >= 0. .fi .PP .br \fIAB\fP .PP .nf AB is COMPLEX array, dimension (LDAB,N) On entry, the matrix A in band storage, in rows 1 to KL+KU+1. The j-th column of A is stored in the j-th column of the array AB as follows: AB(KU+1+i-j,j) = A(i,j) for max(1,j-KU)<=i<=min(N,j+kl) .fi .PP .br \fILDAB\fP .PP .nf LDAB is INTEGER The leading dimension of the array AB. LDAB >= KL+KU+1. .fi .PP .br \fIAFB\fP .PP .nf AFB is COMPLEX array, dimension (LDAFB,N) Details of the LU factorization of the band matrix A, as computed by CGBTRF. U is stored as an upper triangular band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and the multipliers used during the factorization are stored in rows KL+KU+2 to 2*KL+KU+1. .fi .PP .br \fILDAFB\fP .PP .nf LDAFB is INTEGER The leading dimension of the array AFB. LDAFB >= 2*KL+KU+1. .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 117 of file cla_gbrpvgrw\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.