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/*=========================================================================
Program: Visualization Toolkit
Module: vtkBoxMuellerRandomSequence.cxx
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
#include "vtkBoxMuellerRandomSequence.h"
#include "vtkMinimalStandardRandomSequence.h"
#include <cassert>
#include "vtkMath.h"
#include "vtkObjectFactory.h"
vtkStandardNewMacro(vtkBoxMuellerRandomSequence);
// ----------------------------------------------------------------------------
vtkBoxMuellerRandomSequence::vtkBoxMuellerRandomSequence()
{
this->UniformSequence=vtkMinimalStandardRandomSequence::New();
this->Value=0;
}
// ----------------------------------------------------------------------------
vtkBoxMuellerRandomSequence::~vtkBoxMuellerRandomSequence()
{
this->UniformSequence->Delete();
}
// ----------------------------------------------------------------------------
double vtkBoxMuellerRandomSequence::GetValue()
{
return this->Value;
}
// ----------------------------------------------------------------------------
void vtkBoxMuellerRandomSequence::Next()
{
this->UniformSequence->Next();
double x=this->UniformSequence->GetValue();
// Make sure x is in (0,1]
while(x==0.0)
{
this->UniformSequence->Next();
x=this->UniformSequence->GetValue();
}
this->UniformSequence->Next();
double y=this->UniformSequence->GetValue();
// Make sure y is in (0,1]
while(y==0.0)
{
this->UniformSequence->Next();
y=this->UniformSequence->GetValue();
}
this->Value=sqrt(-2.0*log(x))*cos(2.0 * vtkMath::Pi()*y);
}
// ----------------------------------------------------------------------------
vtkRandomSequence *vtkBoxMuellerRandomSequence::GetUniformSequence()
{
assert("post: result_exists" && this->UniformSequence!=0);
return this->UniformSequence;
}
// ----------------------------------------------------------------------------
// Description:
// Set the uniformly distributed sequence of random numbers.
// Default is a .
void vtkBoxMuellerRandomSequence::SetUniformSequence(
vtkRandomSequence *uniformSequence)
{
assert("pre: uniformSequence_exists" && uniformSequence!=0);
if(this->UniformSequence!=uniformSequence)
{
this->UniformSequence->Delete();
this->UniformSequence=uniformSequence;
this->UniformSequence->Register(this);
}
assert("post: assigned" && uniformSequence==this->GetUniformSequence());
}
// ----------------------------------------------------------------------------
void vtkBoxMuellerRandomSequence::PrintSelf(ostream& os, vtkIndent indent)
{
this->Superclass::PrintSelf(os, indent);
}
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