// needed for CemhydMat
void
NonStationaryTransportProblem :: averageOverElements(TimeStep *tStep)
{
    Domain *domain = this->giveDomain(1);
    int ielem, i;
    int nelem = domain->giveNumberOfElements();
    double dV;
    TransportElement *element;
    IntegrationRule *iRule;
    GaussPoint *gp;
    FloatArray vecTemperature;
    TransportMaterial *mat;




    for ( ielem = 1; ielem <= nelem; ielem++ ) {
        element = ( TransportElement * ) domain->giveElement(ielem);
        mat = ( TransportMaterial * ) element->giveMaterial();
        if ( mat->giveClassID() == CemhydMatClass ) {
            iRule = element->giveDefaultIntegrationRulePtr();
            for ( i = 0; i < iRule->getNumberOfIntegrationPoints(); i++ ) {
                gp  = iRule->getIntegrationPoint(i);
                dV  = element->computeVolumeAround(gp);
                element->giveIPValue(vecTemperature, gp, IST_Temperature, tStep);
                //mat->IP_volume += dV;
                //mat->average_temp += vecState.at(1) * dV;
            }
        }
    }

    for ( i = 1; i <= domain->giveNumberOfMaterialModels(); i++ ) {
        mat = ( TransportMaterial * ) domain->giveMaterial(i);
        if ( mat->giveClassID() == CemhydMatClass ) {
            //mat->average_temp /= mat->IP_volume;
        }
    }
}