Functional test to compare SpecularSimulation with various axes

Redmine: #2155

Tests/Functional/Core/CoreSpecial/AxisComparisonTest.cpp

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Tests/Functional/Core/CoreSpecial/AxisComparisonTest.cpp
+//! @brief     Implements class AxisComparisonTest
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+#include "AxisComparisonTest.h"
+#include "Distributions.h"
+#include "FixedBinAxis.h"
+#include "FootprintFactorSquare.h"
+#include "MultiLayer.h"
+#include "ParameterPattern.h"
+#include "PointwiseAxis.h"
+#include "SampleBuilderFactory.h"
+#include "SpecularSimulation.h"
+#include "Units.h"
+
+namespace  {
+const double error_tolerance = 1e-10;
+double relative_difference(double ref, double value)
+{
+    return std::abs(2.0 * (ref - value) / (ref + value));
+}
+}
+
+AxisComparisonTest::AxisComparisonTest() = default;
+AxisComparisonTest::~AxisComparisonTest() = default;
+
+std::unique_ptr<Simulation> AxisComparisonTest::createSimulation(const IAxis& axis)
+{
+const double wavelength = 1.54 * Units::angstrom;
+const size_t n_integration_points = 5;
+const auto square_ff = std::make_unique<FootprintFactorSquare>(0.1);
+const DistributionGaussian alpha_distr(0.0, 0.1*Units::degree);
+
+std::unique_ptr<SpecularSimulation> result(new SpecularSimulation());
+result->setBeamParameters(wavelength, axis, square_ff.get());
+
+ParameterPattern pattern;
+pattern.beginsWith("*").add(BornAgain::BeamType).add(BornAgain::Inclination);
+result->addParameterDistribution(pattern.toStdString(), alpha_distr, n_integration_points);
+
+std::unique_ptr<MultiLayer> sample(
+    SampleBuilderFactory().createSample("PlainMultiLayerBySLDBuilder"));
+result->setSample(*sample);
+
+result->runSimulation();
+
+return result;
+}
+
+bool AxisComparisonTest::runTest()
+{
+    // creating reference simulation
+    FixedBinAxis axis("reference", 10, 0.0, 10.0 * Units::degree);
+    auto reference = createSimulation(axis);
+
+    // simulation with poinwise axis
+    const std::vector<size_t> mask {0u, 2u, 3u, 4u, 7u, 8u, 9u};
+    std::vector<double> coordinates;
+    for (auto index: mask)
+        coordinates.push_back(axis.getBinCenter(index));
+    PointwiseAxis pointwise_axis("pointwise", coordinates);
+    auto pointwise_simulation = createSimulation(pointwise_axis);
+
+    // comparing simulations
+    auto ref_result = reference->result();
+    auto pointwise_result = pointwise_simulation->result();
+    for (size_t i = 0; i < mask.size(); ++i) {
+        double rel_error = relative_difference(ref_result[mask[i]], pointwise_result[i]);
+        if (std::abs(rel_error) > error_tolerance) {
+            std::cout << "AxisComparisonTest: " << "Relative error " << rel_error <<
+                         " Exceeds error tolerance " << error_tolerance << std::endl;
+            return false;
+        }
+    }
+    return true;
+}

Tests/Functional/Core/CoreSpecial/AxisComparisonTest.h

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Tests/Functional/Core/CoreSpecial/AxisComparisonTest.h
+//! @brief     Defines class AxisComparisonTest
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+#ifndef AXISCOMPARISONTEST_H
+#define AXISCOMPARISONTEST_H
+
+#include "IFunctionalTest.h"
+#include <memory>
+
+class IAxis;
+class Simulation;
+
+class AxisComparisonTest : public IFunctionalTest
+{
+public:
+    AxisComparisonTest();
+    ~AxisComparisonTest() override;
+    static std::unique_ptr<Simulation> createSimulation(const IAxis& axis);
+
+private:
+    bool runTest() override;
+};
+
+#endif // AXISCOMPARISONTEST_H

Tests/Functional/Core/CoreSpecial/CMakeLists.txt

@@ -4,6 +4,7 @@ set(test_cases
     BatchSimulation
     PolDWBAMagCylinders
     FourierTransformation
+    AxisComparisonTest
 #    CoreIO
 #    DetectorTest
 #    MesoPerformance

Tests/Functional/Core/CoreSpecial/CoreSpecialTestFactory.cpp

@@ -13,6 +13,7 @@
 // ************************************************************************** //
 
 #include "CoreSpecialTestFactory.h"
+#include "AxisComparisonTest.h"
 #include "BatchSimulation.h"
 #include "DetectorTest.h"
 #include "PolDWBAMagCylinders.h"
@@ -45,4 +46,8 @@ CoreSpecialTestFactory::CoreSpecialTestFactory()
     registerItem("MesoPerformance",
                  create_new<MesoCrystalPerformanceTest>,
                  "Heavy mesocrystal simulation");
+
+    registerItem("AxisComparisonTest",
+                 create_new<AxisComparisonTest>,
+                 "Comparing simulation results for FixedBinAxis and PointwiseAxis");
 }