Method RequestData

Infovis/BoostGraphAlgorithms/vtkBoostRandomSparseArraySource.cxx:67–103

//------------------------------------------------------------------------------

int vtkBoostRandomSparseArraySource::RequestData(
  vtkInformation*, vtkInformationVector**, vtkInformationVector* outputVector)
{
  boost::mt19937 pattern_generator(static_cast<boost::uint32_t>(this->ElementProbabilitySeed));
  boost::bernoulli_distribution<> pattern_distribution(this->ElementProbability);
  boost::variate_generator<boost::mt19937&, boost::bernoulli_distribution<>> pattern(
    pattern_generator, pattern_distribution);

  boost::mt19937 value_generator(static_cast<boost::uint32_t>(this->ElementValueSeed));
  boost::uniform_real<> value_distribution(this->MinValue, this->MaxValue);
  boost::variate_generator<boost::mt19937&, boost::uniform_real<>> values(
    value_generator, value_distribution);

  vtkSparseArray<double>* const array = vtkSparseArray<double>::New();
  array->Resize(this->Extents);

  vtkArrayCoordinates coordinates;
  for (vtkArray::SizeT n = 0; n != this->Extents.GetSize(); ++n)
  {
    this->Extents.GetRightToLeftCoordinatesN(n, coordinates);

    // Although it seems wasteful, we calculate a value for every element in the array
    // so the results stay consistent as the ElementProbability varies
    const double value = values();
    if (pattern())
    {
      array->AddValue(coordinates, value);
    }
  }

  vtkArrayData* const output = vtkArrayData::GetData(outputVector);
  output->ClearArrays();
  output->AddArray(array);
  array->Delete();

  return 1;
}
VTK_ABI_NAMESPACE_END