.TH "SRC/zgbcon.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zgbcon.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzgbcon\fP (norm, n, kl, ku, ab, ldab, ipiv, anorm, rcond, work, rwork, info)" .br .RI "\fBZGBCON\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zgbcon (character norm, integer n, integer kl, integer ku, complex*16, dimension( ldab, * ) ab, integer ldab, integer, dimension( * ) ipiv, double precision anorm, double precision rcond, complex*16, dimension( * ) work, double precision, dimension( * ) rwork, integer info)" .PP \fBZGBCON\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZGBCON estimates the reciprocal of the condition number of a complex !> general band matrix A, in either the 1-norm or the infinity-norm, !> using the LU factorization computed by ZGBTRF\&. !> !> An estimate is obtained for norm(inv(A)), and the reciprocal of the !> condition number is computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) )\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> 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 \fIAB\fP .PP .nf !> AB is COMPLEX*16 array, dimension (LDAB,N) !> Details of the LU factorization of the band matrix A, as !> computed by ZGBTRF\&. 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 \fILDAB\fP .PP .nf !> LDAB is INTEGER !> The leading dimension of the array AB\&. LDAB >= 2*KL+KU+1\&. !> .fi .PP .br \fIIPIV\fP .PP .nf !> IPIV is INTEGER array, dimension (N) !> The pivot indices; for 1 <= i <= N, row i of the matrix was !> interchanged with row IPIV(i)\&. !> .fi .PP .br \fIANORM\fP .PP .nf !> ANORM is DOUBLE PRECISION !> If NORM = '1' or 'O', the 1-norm of the original matrix A\&. !> If NORM = 'I', the infinity-norm of the original matrix A\&. !> .fi .PP .br \fIRCOND\fP .PP .nf !> RCOND is DOUBLE PRECISION !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A)))\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX*16 array, dimension (2*N) !> .fi .PP .br \fIRWORK\fP .PP .nf !> RWORK is DOUBLE PRECISION array, dimension (N) !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> .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 .PP Definition at line \fB145\fP of file \fBzgbcon\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.