Function ComponentOrNormAsArray

Common/Core/vtkArrayComponents.cxx:252–325

}

vtkSmartPointer<vtkAbstractArray> ComponentOrNormAsArray(vtkAbstractArray* array, int compOrNorm)
{
  vtkSmartPointer<vtkAbstractArray> result;
  if (!array)
  {
    return result;
  }
  if (compOrNorm == vtkArrayComponents::AllComponents ||
    (array->GetNumberOfComponents() == 1 && compOrNorm == 0))
  {
    // Return the input array; don't create a new one since it would be an identical copy.
    result = array;
  }
  else
  {
    if (auto dataArray = vtkDataArray::SafeDownCast(array))
    {
      switch (compOrNorm)
      {
        case vtkArrayComponents::L1Norm:
          result = computeL1Norm(dataArray);
          break;
        case vtkArrayComponents::L2Norm:
          result = computeL2Norm(dataArray);
          break;
        case vtkArrayComponents::LInfNorm:
          result = computeLInfNorm(dataArray);
          break;
        default:
        {
          if (compOrNorm >= 0 && compOrNorm < array->GetNumberOfComponents())
          {
            result.TakeReference(array->NewInstance());
            result->SetNumberOfComponents(1);
            result->SetNumberOfTuples(array->GetNumberOfTuples());
            result->CopyComponent(0, array, compOrNorm);
          }
          else
          {
            vtkErrorWithObjectMacro(array, "Invalid component " << compOrNorm << " requested.");
          }
        }
        break;
      }
      if (result)
      {
        std::string aname = arrayName(array);
        std::string cname = componentName(array, compOrNorm);
        result->SetName((aname + "_" + cname).c_str());
      }
    }
    else
    {
      // Variant and string arrays do not provide a norm nor allow an out-of-range component.
      if (compOrNorm < 0 || compOrNorm >= array->GetNumberOfComponents())
      {
        vtkErrorWithObjectMacro(array,
          "Request for an non-existent component or a norm on an array that does not support it.");