table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/zlantb.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/zlantb.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/zlantb.f
SYNOPSIS¶
Functions/Subroutines¶
double precision function ZLANTB (norm, uplo, diag, n, k,
ab, ldab, work)
ZLANTB returns the value of the 1-norm, or the Frobenius norm, or the
infinity norm, or the element of largest absolute value of a triangular band
matrix.
Function/Subroutine Documentation¶
double precision function ZLANTB (character norm, character uplo, character diag, integer n, integer k, complex*16, dimension( ldab, * ) ab, integer ldab, double precision, dimension( * ) work)¶
ZLANTB returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular band matrix.
Purpose:
!> !> ZLANTB 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 triangular band matrix A, with ( k + 1 ) diagonals. !>
Returns
ZLANTB
!> !> ZLANTB = ( 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. !>
Parameters
NORM
!> NORM is CHARACTER*1 !> Specifies the value to be returned in ZLANTB as described !> above. !>
UPLO
!> UPLO is CHARACTER*1 !> Specifies whether the matrix A is upper or lower triangular. !> = 'U': Upper triangular !> = 'L': Lower triangular !>
DIAG
!> DIAG is CHARACTER*1 !> Specifies whether or not the matrix A is unit triangular. !> = 'N': Non-unit triangular !> = 'U': Unit triangular !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. When N = 0, ZLANTB is !> set to zero. !>
K
!> K is INTEGER !> The number of super-diagonals of the matrix A if UPLO = 'U', !> or the number of sub-diagonals of the matrix A if UPLO = 'L'. !> K >= 0. !>
AB
!> AB is COMPLEX*16 array, dimension (LDAB,N) !> The upper or lower triangular band matrix A, stored in the !> first k+1 rows of AB. The j-th column of A is stored !> in the j-th column of the array AB as follows: !> if UPLO = 'U', AB(k+1+i-j,j) = A(i,j) for max(1,j-k)<=i<=j; !> if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+k). !> Note that when DIAG = 'U', the elements of the array AB !> corresponding to the diagonal elements of the matrix A are !> not referenced, but are assumed to be one. !>
LDAB
!> LDAB is INTEGER !> The leading dimension of the array AB. LDAB >= K+1. !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)), !> where LWORK >= N when NORM = 'I'; otherwise, WORK is not !> referenced. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 139 of file zlantb.f.
Author¶
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.12.0 | LAPACK |