functionreorderZeros

Extract real and conjugate complex elements from a complex vector

Extends from Modelica.Icons.Function (Icon for functions).

Information

Syntax

               reorderedZero = Internal.reorderZeros(complexVector);
(reorderedZeros, nRealZeros) = Internal.reorderZeros(complexVector,
                                                     name="complexVector");

Description

Function reorderZeros(..) reorders the zeros from the Complex vector "complexVector" such that the returned Complex vector reorderedZeros contains first all real Zeros and afterwards the conjugate complex zero pairs. It is required that all elements of complexVector define either a real zero (complexVector[i].im=0) or a conjugate complex zero pair (complexVector[i].re == complexVector[i+1].re and complexVector[i].im == -complexVector[i+1].im). The optional input argument "name" is used as name of "complexVector" in error messages.

The function returns the vector element reordered, as well as the number of real zeros (nRealZeros).

Example

  // c = {0, 1+2*j, 1-2*j, 2, -3, -1-1*j, -1+1*j};
  Real complexZeros[:] = fill(Complex(0), integer((size(c,1)-n)/2));
algorithm
  (reorderedZeros, nRealZeros) := reorderZeros(c);
  // reorderedZeros = {0, 2, (-3), 1+2*j, 1-2*j, -1+1*j, -1-1*j}
  // nRealZeros     = 3

Inputs

Type	Name	Default	Description
Complex[:]	complexVector		Zeros of a polynomial with real coefficients, e.g., eigen values of a real matrix
String	name	"complexVector"	Name of complexVector to be used in error message

Outputs

Type	Name	Default	Description
Complex[size(complexVector, 1)]	reorderedZeros		Reordered zeros
Integer	nRealZeros	numberOfRealZeros(complexVector)	Number of real zeros (reorderedZeros[1:nRealZeros] are the real zeros)