tmp<vectorField> FaceSetValueExpressionDriver::makePositionField() const
{
    return getFromFieldInternal(this->mesh().Cf(),faceSet_());
}
vectorField *CellSetValueExpressionDriver::makePositionField()
{
    return getFromFieldInternal(this->mesh().C(),cellSet_());
}
tmp<scalarField> CellSetValueExpressionDriver::makeCellVolumeField() const
{
    return getFromFieldInternal(this->mesh().V(),cellSet_());
}
vectorField *FaceZoneValueExpressionDriver::makeFaceAreaField()
{
    return getFromFieldInternal(this->mesh().Sf(),faceZone_);
}