mirror of
https://git.dev.opencascade.org/repos/occt.git
synced 2025-06-05 11:24:17 +03:00
108 lines
3.3 KiB
C++
Executable File
108 lines
3.3 KiB
C++
Executable File
// Created on: 2005-12-19
|
|
// Created by: Julia GERASIMOVA
|
|
// Copyright (c) 2005-2012 OPEN CASCADE SAS
|
|
//
|
|
// The content of this file is subject to the Open CASCADE Technology Public
|
|
// License Version 6.5 (the "License"). You may not use the content of this file
|
|
// except in compliance with the License. Please obtain a copy of the License
|
|
// at http://www.opencascade.org and read it completely before using this file.
|
|
//
|
|
// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
|
|
// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
|
|
//
|
|
// The Original Code and all software distributed under the License is
|
|
// distributed on an "AS IS" basis, without warranty of any kind, and the
|
|
// Initial Developer hereby disclaims all such warranties, including without
|
|
// limitation, any warranties of merchantability, fitness for a particular
|
|
// purpose or non-infringement. Please see the License for the specific terms
|
|
// and conditions governing the rights and limitations under the License.
|
|
|
|
|
|
|
|
#include <math_ComputeGaussPointsAndWeights.ixx>
|
|
|
|
#include <math_EigenValuesSearcher.hxx>
|
|
#include <math_Array1OfValueAndWeight.hxx>
|
|
#include <math_CompareOfValueAndWeight.hxx>
|
|
#include <math_QuickSortOfValueAndWeight.hxx>
|
|
#include <Standard_ErrorHandler.hxx>
|
|
|
|
math_ComputeGaussPointsAndWeights::math_ComputeGaussPointsAndWeights(const Standard_Integer Number)
|
|
{
|
|
myIsDone = Standard_False;
|
|
|
|
try {
|
|
myPoints = new TColStd_HArray1OfReal(1, Number);
|
|
myWeights = new TColStd_HArray1OfReal(1, Number);
|
|
|
|
Standard_Integer i;
|
|
|
|
TColStd_Array1OfReal aDiag(1, Number);
|
|
TColStd_Array1OfReal aSubDiag(1, Number);
|
|
|
|
//Initialization of a real symmetric tridiagonal matrix for
|
|
//computation of Gauss quadrature.
|
|
|
|
for (i = 1; i <= Number; i++) {
|
|
aDiag(i) = 0.;
|
|
|
|
if (i == 1)
|
|
aSubDiag(i) = 0.;
|
|
else {
|
|
Standard_Integer sqrIm1 = (i-1)*(i-1);
|
|
aSubDiag(i) = sqrIm1/(4.*sqrIm1 - 1);
|
|
aSubDiag(i) = Sqrt(aSubDiag(i));
|
|
}
|
|
}
|
|
|
|
// Compute eigen values.
|
|
math_EigenValuesSearcher EVsearch(aDiag, aSubDiag);
|
|
|
|
if (EVsearch.IsDone()) {
|
|
math_Array1OfValueAndWeight VWarray(1, Number);
|
|
for (i = 1; i <= Number; i++) {
|
|
math_Vector anEigenVector = EVsearch.EigenVector(i);
|
|
Standard_Real aWeight = anEigenVector(1);
|
|
aWeight = 2. * aWeight * aWeight;
|
|
math_ValueAndWeight EVW( EVsearch.EigenValue(i), aWeight );
|
|
VWarray(i) = EVW;
|
|
}
|
|
|
|
math_CompareOfValueAndWeight theComparator;
|
|
math_QuickSortOfValueAndWeight::Sort(VWarray, theComparator);
|
|
|
|
for (i = 1; i <= Number; i++) {
|
|
myPoints->ChangeValue(i) = VWarray(i).Value();
|
|
myWeights->ChangeValue(i) = VWarray(i).Weight();
|
|
}
|
|
myIsDone = Standard_True;
|
|
}
|
|
} catch (Standard_Failure) {
|
|
}
|
|
}
|
|
|
|
Standard_Boolean math_ComputeGaussPointsAndWeights::IsDone() const
|
|
{
|
|
return myIsDone;
|
|
}
|
|
|
|
math_Vector math_ComputeGaussPointsAndWeights::Points() const
|
|
{
|
|
Standard_Integer Number = myPoints->Length();
|
|
math_Vector thePoints(1, Number);
|
|
for (Standard_Integer i = 1; i <= Number; i++)
|
|
thePoints(i) = myPoints->Value(i);
|
|
|
|
return thePoints;
|
|
}
|
|
|
|
math_Vector math_ComputeGaussPointsAndWeights::Weights() const
|
|
{
|
|
Standard_Integer Number = myWeights->Length();
|
|
math_Vector theWeights(1, Number);
|
|
for (Standard_Integer i = 1; i <= Number; i++)
|
|
theWeights(i) = myWeights->Value(i);
|
|
|
|
return theWeights;
|
|
}
|