Method ReduceValuesToMedian

Infovis/Core/vtkReduceTable.cxx:208–238

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkReduceTable::ReduceValuesToMedian(
  vtkTable* input, vtkTable* output, vtkIdType row, vtkIdType col, std::vector<vtkIdType> oldRows)
{
  if (!input->GetValue(0, col).IsNumeric())
  {
    vtkErrorMacro(<< "Median is unsupported for non-numerical data");
    return;
  }

  // generate a vector of values
  std::vector<double> values;
  for (std::vector<vtkIdType>::iterator itr = oldRows.begin(); itr != oldRows.end(); ++itr)
  {
    values.push_back(input->GetValue(*itr, col).ToDouble());
  }

  // sort it
  std::sort(values.begin(), values.end());

  // get the median and store it in the output table
  if (values.size() % 2 == 1)
  {
    output->SetValue(row, col, vtkVariant(values.at((values.size() - 1) / 2)));
  }
  else
  {
    double d1 = values.at((values.size() - 1) / 2);
    double d2 = values.at(values.size() / 2);
    output->SetValue(row, col, vtkVariant((d1 + d2) / 2.0));
  }
}

//------------------------------------------------------------------------------
void vtkReduceTable::ReduceValuesToMode(