DGUtilsTest.cpp

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#include "DGUtilsTest.h"
#include "TestUtils.h"
#include "../DGUtils.h"
 
#include "peano4/datamanagement/CellMarker.h"
 
 
/*
 * We use precomputed values for lagrange polynomials as basis function
 *  on Gauss-Legendre nodes
 */
exahype2::dg::tests::DGUtilsTest::DGUtilsTest():
  TestCase ("exahype2::dg::tests::DGUtilsTest") {
}
 
 
void exahype2::dg::tests::DGUtilsTest::run(){
  testMethod( testGetIndex );
  testMethod( testComputeGradientOnConstantSolution );
  testMethod( testEvaluatePolynomialOrder1 );
  testMethod( testEvaluatePolynomialOrder2 );
}
 
 
void exahype2::dg::tests::DGUtilsTest::testEvaluatePolynomialOrder1() {
  const int order = 1;
 
  peano4::grid::GridTraversalEvent    dummyEvent;
 
  #if Dimensions==2
  dummyEvent.setX( {0.4,0.6} );
  dummyEvent.setH( {0.2,0.2} );
  double Q0[] = {1.2,1.2,1.2,1.2};
  tarch::la::Vector<Dimensions,double>  xCentre     = {0.5,0.7};
  tarch::la::Vector<Dimensions,double>  xLeftBottom = {0.4+0.2*QuadratureNodes1dP1[0],0.6+0.2*QuadratureNodes1dP1[0]};
  #else
  dummyEvent.setX( {0.4,0.6,0.8} );
  dummyEvent.setH( {0.2,0.2,0.2} );
  double Q0[] = {1.2,1.2,1.2,1.2,1.2,1.2,1.2,1.2};
  tarch::la::Vector<Dimensions,double>  xCentre = {0.5,0.7,0.9};
  tarch::la::Vector<Dimensions,double>  xLeftBottom = {0.4+0.2*QuadratureNodes1dP1[0],0.6+0.2*QuadratureNodes1dP1[0],0.8+0.2*QuadratureNodes1dP1[0]};
  #endif
 
  peano4::datamanagement::CellMarker  cellMarker(dummyEvent);
 
  double result;
  result = exahype2::dg::evaluatePolynomial(
    cellMarker,
    order,
    QuadratureNodes1dP1,
    1,
    Q0,
    xLeftBottom,
    0
  );
  validateNumericalEqualsWithParams1( result, 1.2, cellMarker.toString() );
 
  result = exahype2::dg::evaluatePolynomial(
    cellMarker,
    order,
    QuadratureNodes1dP1,
    1,
    Q0,
    xCentre,
    0
  );
  validateNumericalEqualsWithParams1( result, 1.2, cellMarker.toString() );
}
 
 
void exahype2::dg::tests::DGUtilsTest::testEvaluatePolynomialOrder2() {
  const int order = 2;
 
  peano4::grid::GridTraversalEvent    dummyEvent;
 
  #if Dimensions==2
  dummyEvent.setX( {0.4,0.6} );
  dummyEvent.setH( {0.2,0.2} );
  double Q0[] = { 1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2 };
  tarch::la::Vector<Dimensions,double>  xCentre     = {0.5,0.7};
  tarch::la::Vector<Dimensions,double>  xLeftBottom = {0.4+0.2*QuadratureNodes1dP2[0],0.6+0.2*QuadratureNodes1dP2[0]};
  #else
  dummyEvent.setX( {0.4,0.6,0.8} );
  dummyEvent.setH( {0.2,0.2,0.2} );
  double Q0[] = { 1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2,
                  1.2, 1.2, 1.2 };
  tarch::la::Vector<Dimensions,double>  xCentre = {0.5,0.7,0.9};
  tarch::la::Vector<Dimensions,double>  xLeftBottom = {0.4+0.2*QuadratureNodes1dP1[0],0.6+0.2*QuadratureNodes1dP1[0],0.8+0.2*QuadratureNodes1dP1[0]};
  #endif
 
  peano4::datamanagement::CellMarker  cellMarker(dummyEvent);
 
  double result;
  result = exahype2::dg::evaluatePolynomial(
    cellMarker,
    order,
    QuadratureNodes1dP2,
    1,
    Q0,
    xLeftBottom,
    0
  );
  validateNumericalEqualsWithParams1( result, 1.2, cellMarker.toString() );
 
  result = exahype2::dg::evaluatePolynomial(
    cellMarker,
    order,
    QuadratureNodes1dP2,
    1,
    Q0,
    xCentre,
    0
  );
  validateNumericalEqualsWithParams1( result, 1.2, cellMarker.toString() );
}
 
 
void exahype2::dg::tests::DGUtilsTest::testGetIndex() {
  const int order = 3;
  const int nodesPerAxis = order+1;
  const int nodesPerCell = getNodesPerCell(nodesPerAxis);
 
  validateEquals(nodesPerCell, std::pow(nodesPerAxis,Dimensions));
 
  tarch::la::Vector<Dimensions,int> strides = getStrides(nodesPerAxis);
  validateEquals(strides[Dimensions-1], std::pow(nodesPerAxis,Dimensions-1));
 
  tarch::la::Vector<Dimensions,int> firstIndex = getIndex(0, strides);
  for(int i=0; i<Dimensions; i++){
    validateEquals(firstIndex[i], 0);
  }
 
  tarch::la::Vector<Dimensions,int> lastIndex = getIndex(nodesPerCell-1, strides);
  for(int i=0; i<Dimensions; i++){
    validateEquals(lastIndex[i], nodesPerAxis-1);
  }
}
 
 
void exahype2::dg::tests::DGUtilsTest::testComputeGradientOnConstantSolution() {
  #if Dimensions==2
  const int order        = 3;
  const int nodesPerAxis = order+1;
  const int nodesPerCell = getNodesPerCell(nodesPerAxis);
 
  // 1 unknown, 1 auxiliary variable
  double cellQin[2*nodesPerCell];
  double gradientValues[2*Dimensions];
  for(int i=0; i<2*nodesPerCell; i++){
    cellQin[i] = 1.0;
  }
 
  for(int node=0; node<nodesPerCell; node++){
    computeGradient(
      cellQin,
      DerivativeOperatorLagrangeP3,
      10, //invDx
      nodesPerAxis,
      2, //strideQ
      node,
      gradientValues
      );
    for(int var=0; var<Dimensions; var++){
      validateNumericalEquals(gradientValues[var], 0.0);
    }
  }
  #endif
}