WOLFRAM SYSTEM MODELER

# dlange

Norm of a matrix # Wolfram Language

In:= `SystemModel["Modelica.Math.Matrices.LAPACK.dlange"]`
Out:= # Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

```Lapack documentation
Purpose
=======

DLANGE  returns the value of the one norm,  or the Frobenius norm, or
the  infinity norm,  or the  element of  largest absolute value  of a
real matrix A.

Description
===========

DLANGE returns the value

DLANGE = ( 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.

Arguments
=========

NORM    (input) CHARACTER*1
Specifies the value to be returned in DLANGE as described
above.

M       (input) INTEGER
The number of rows of the matrix A.  M >= 0.  When M = 0,
DLANGE is set to zero.

N       (input) INTEGER
The number of columns of the matrix A.  N >= 0.  When N = 0,
DLANGE is set to zero.

A       (input) DOUBLE PRECISION array, dimension (LDA,N)
The m by n matrix A.

LDA     (input) INTEGER
The leading dimension of the array A.  LDA >= max(M,1).

WORK    (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)),
where LWORK >= M when NORM = 'I'; otherwise, WORK is not
referenced.```

# Syntax

anorm = dlange(A, norm)

# Inputs (2)

A Type: Real[:,:] Description: Real matrix A Default Value: "1" Type: String Description: specifies the norm, i.e., 1, I, F, M

# Outputs (1)

anorm Type: Real Description: norm of A