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DLANSBRun Method

Purpose ======= DLANSB 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 symmetric band matrix A, with k super-diagonals. Description =========== DLANSB returns the value DLANSB = ( 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.

Namespace: DotNumerics.LinearAlgebra.CSLapack
Assembly: DWSIM.MathOps.DotNumerics (in DWSIM.MathOps.DotNumerics.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax
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public double Run(
	string NORM,
	string UPLO,
	int N,
	int K,
	double[] AB,
	int offset_ab,
	int LDAB,
	ref double[] WORK,
	int offset_work
)
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Parameters

NORM  String
(input) CHARACTER*1 Specifies the value to be returned in DLANSB as described above.
UPLO  String
(input) CHARACTER*1 Specifies whether the upper or lower triangular part of the band matrix A is supplied. = 'U': Upper triangular part is supplied = 'L': Lower triangular part is supplied
N  Int32
(input) INTEGER The order of the matrix A. N .GE. 0. When N = 0, DLANSB is set to zero.
K  Int32
(input) INTEGER The number of super-diagonals or sub-diagonals of the band matrix A. K .GE. 0.
AB  Double
(input) DOUBLE PRECISION array, dimension (LDAB,N) The upper or lower triangle of the symmetric 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).LE.i.LE.j; if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j.LE.i.LE.min(n,j+k).
offset_ab  Int32
 
LDAB  Int32
(input) INTEGER The leading dimension of the array AB. LDAB .GE. K+1.
WORK  Double
(workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK .GE. N when NORM = 'I' or '1' or 'O'; otherwise, WORK is not referenced.
offset_work  Int32
 

Return Value

Double
See Also