WOLFRAM

WOLFRAM SYSTEM MODELER

rcond

Return the reciprocal condition number of a matrix

Wolfram Language

In[1]:=
SystemModel["Modelica.Math.Matrices.rcond"]
Out[1]:=

Information

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

Syntax

r = Matrices.rcond(A);

Description

This function estimates the reciprocal of the condition number (norm(A) * norm(inv(A))) of a general real matrix A, in either the 1-norm or the infinity-norm, using the LAPACK function DGECON. If rcond(A) is near 1.0, A is well conditioned and A is ill conditioned if rcond(A) is near zero.

Example

A = [1, 2;
     2, 1];
r = rcond(A);

results in:

r = 0.3333

See also

Matrices.conditionNumber

Syntax

(rcond, info) = rcond(A, inf)

Inputs (2)

A

Type: Real[:,size(A, 1)]

Description: Square real matrix
inf

Default Value: false

Type: Boolean

Description: Is true if infinity norm is used and false for 1-norm

Outputs (2)

rcond

Type: Real

Description: Reciprocal condition number of A
info

Type: Integer

Description: Information

Revisions

  • 2010/05/31 by Marcus Baur, DLR-RM