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DLANTRRun Method

Purpose ======= DLANTR returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix A. Description =========== DLANTR returns the value DLANTR = ( 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 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
Copy
public double Run(
	string NORM,
	string UPLO,
	string DIAG,
	int M,
	int N,
	double[] A,
	int offset_a,
	int LDA,
	ref double[] WORK,
	int offset_work
)
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Parameters

NORM  String
(input) CHARACTER*1 Specifies the value to be returned in DLANTR as described above.
UPLO  String
(input) CHARACTER*1 Specifies whether the matrix A is upper or lower trapezoidal. = 'U': Upper trapezoidal = 'L': Lower trapezoidal Note that A is triangular instead of trapezoidal if M = N.
DIAG  String
(input) CHARACTER*1 Specifies whether or not the matrix A has unit diagonal. = 'N': Non-unit diagonal = 'U': Unit diagonal
M  Int32
(input) INTEGER The number of rows of the matrix A. M .GE. 0, and if UPLO = 'U', M .LE. N. When M = 0, DLANTR is set to zero.
N  Int32
(input) INTEGER The number of columns of the matrix A. N .GE. 0, and if UPLO = 'L', N .LE. M. When N = 0, DLANTR is set to zero.
A  Double
(input) DOUBLE PRECISION array, dimension (LDA,N) The trapezoidal matrix A (A is triangular if M = N). If UPLO = 'U', the leading m by n upper trapezoidal part of the array A contains the upper trapezoidal matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading m by n lower trapezoidal part of the array A contains the lower trapezoidal matrix, and the strictly upper triangular part of A is not referenced. Note that when DIAG = 'U', the diagonal elements of A are not referenced and are assumed to be one.
offset_a  Int32
 
LDA  Int32
(input) INTEGER The leading dimension of the array A. LDA .GE. max(M,1).
WORK  Double
(workspace) DOUBLE PRECISION array, dimension (LWORK), where LWORK .GE. M when NORM = 'I'; otherwise, WORK is not referenced.
offset_work  Int32
 

Return Value

Double
See Also