Method EvaluateFunction

Common/DataModel/vtkImplicitDataSet.cxx:41–82

Evaluate the implicit function. This returns the interpolated scalar value at x[3].

// Evaluate the implicit function. This returns the interpolated scalar value
// at x[3].
double vtkImplicitDataSet::EvaluateFunction(double x[3])
{
  vtkDataArray* scalars;
  vtkCell* cell;
  vtkIdType id;
  int subId, i, numPts;
  double pcoords[3], s;

  // See if a dataset has been specified
  if (!this->DataSet || !(scalars = this->DataSet->GetPointData()->GetScalars()))
  {
    vtkErrorMacro(
      << "Can't evaluate function: either data set is missing or data set has no point data");
    return this->OutValue;
  }

  if (this->DataSet->GetMaxCellSize() > this->Size)
  {
    delete[] this->Weights;
    this->Weights = new double[this->DataSet->GetMaxCellSize()];
    this->Size = this->DataSet->GetMaxCellSize();
  }

  // Find the cell that contains xyz and get it
  cell =
    this->DataSet->FindAndGetCell(x, nullptr, -1, VTK_DBL_EPSILON, subId, pcoords, this->Weights);

  if (cell)
  { // Interpolate the point data
    numPts = cell->GetNumberOfPoints();
    for (s = 0.0, i = 0; i < numPts; i++)
    {
      id = cell->PointIds->GetId(i);
      s += scalars->GetComponent(id, 0) * this->Weights[i];
    }
    return s;
  }
  else
  { // use outside value
    return this->OutValue;
  }
}

vtkMTimeType vtkImplicitDataSet::GetMTime()
{