.TH "SRC/zlangb.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zlangb.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "double precision function \fBzlangb\fP (norm, n, kl, ku, ab, ldab, work)" .br .RI "\fBZLANGB\fP returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of general band matrix\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "double precision function zlangb (character norm, integer n, integer kl, integer ku, complex*16, dimension( ldab, * ) ab, integer ldab, double precision, dimension( * ) work)" .PP \fBZLANGB\fP returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of general band matrix\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZLANGB returns the value of the one norm, or the Frobenius norm, or !> the infinity norm, or the element of largest absolute value of an !> n by n band matrix A, with kl sub-diagonals and ku super-diagonals\&. !> .fi .PP .RE .PP \fBReturns\fP .RS 4 ZLANGB .PP .nf !> !> ZLANGB = ( max(abs(A(i,j))), NORM = 'M' or 'm' !> ( !> ( norm1(A), NORM = '1', 'O' or 'o' !> ( !> ( normI(A), NORM = 'I' or 'i' !> ( !> ( normF(A), NORM = 'F', 'f', 'E' or 'e' !> !> where norm1 denotes the one norm of a matrix (maximum column sum), !> normI denotes the infinity norm of a matrix (maximum row sum) and !> normF denotes the Frobenius norm of a matrix (square root of sum of !> squares)\&. Note that max(abs(A(i,j))) is not a consistent matrix norm\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies the value to be returned in ZLANGB as described !> above\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The order of the matrix A\&. N >= 0\&. When N = 0, ZLANGB is !> set to zero\&. !> .fi .PP .br \fIKL\fP .PP .nf !> KL is INTEGER !> The number of sub-diagonals of the matrix A\&. KL >= 0\&. !> .fi .PP .br \fIKU\fP .PP .nf !> KU is INTEGER !> The number of super-diagonals of the matrix A\&. KU >= 0\&. !> .fi .PP .br \fIAB\fP .PP .nf !> AB is COMPLEX*16 array, dimension (LDAB,N) !> The band matrix A, stored 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 \fIWORK\fP .PP .nf !> WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)), !> where LWORK >= N when NORM = 'I'; otherwise, WORK is not !> referenced\&. !> .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 \fB123\fP of file \fBzlangb\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.