first commit

test_suite/unit_tests/FDM/CMakeLists.txt

@@ -0,0 +1,18 @@
+set(TESTSUITE_SOURCES
+    ${TESTSUITE_SOURCES}
+    ${CMAKE_CURRENT_SOURCE_DIR}/TestSuite.cxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_ls_matrix.cxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testAeroElement.cxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testYASimAtmosphere.cxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testYASimGear.cxx
+    PARENT_SCOPE
+)
+
+set(TESTSUITE_HEADERS
+    ${TESTSUITE_HEADERS}
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_ls_matrix.hxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testAeroElement.hxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testYASimAtmosphere.hxx
+    ${CMAKE_CURRENT_SOURCE_DIR}/testYASimGear.hxx
+    PARENT_SCOPE
+)

test_suite/unit_tests/FDM/TestSuite.cxx

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 Edward d'Auvergne
+ *
+ * This file is part of the program FlightGear.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "test_ls_matrix.hxx"
+#include "testAeroElement.hxx"
+#include "testYASimAtmosphere.hxx"
+#include "testYASimGear.hxx"
+
+
+// Set up the unit tests.
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION(AeroElementTests, "Unit tests");
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION(LaRCSimMatrixTests, "Unit tests");
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION(YASimAtmosphereTests, "Unit tests");
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION(YASimGearTests, "Unit tests");

test_suite/unit_tests/FDM/testAeroElement.cxx

@@ -0,0 +1,134 @@
+#include <simgear/constants.h>
+#include <simgear/structure/SGSharedPtr.hxx>
+#include <simgear/math/SGVec3.hxx>
+
+#include "FDM/AIWake/AeroElement.hxx"
+
+#include "testAeroElement.hxx"
+
+
+void AeroElementTests::testNormal()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d n = el->getNormal();
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(n[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(n[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(n[2], -1.0, 1e-9);
+}
+
+void AeroElementTests::testCollocationPoint()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d cp = el->getCollocationPoint();
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(cp[0], -0.75, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(cp[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(cp[2], 0.0, 1e-9);
+}
+
+void AeroElementTests::testBoundVortexMidPoint()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(mp[0], -0.25, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(mp[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(mp[2], 0.0, 1e-9);
+}
+
+void AeroElementTests::testBoundVortex()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d v = el->getBoundVortex();
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 1.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], 0.0, 1e-9);
+}
+
+void AeroElementTests::testInducedVelocityOnBoundVortex()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    SGVec3d v = el->getInducedVelocity(mp);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], 1.0/M_PI, 1e-9);
+}
+
+void AeroElementTests::testInducedVelocityOnCollocationPoint()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d cp = el->getCollocationPoint();
+    SGVec3d v = el->getInducedVelocity(cp);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], (1.0+sqrt(2.0)/M_PI), 1e-9);
+}
+
+void AeroElementTests::testInducedVelocityAtFarField()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    SGVec3d v = el->getInducedVelocity(mp+SGVec3d(-1000.,0.,0.));
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], 2.0/M_PI, 1e-7);
+}
+
+void AeroElementTests::testInducedVelocityAbove()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    SGVec3d v = el->getInducedVelocity(mp+SGVec3d(0.,0.,-0.5));
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], -1.0/(sqrt(2.0)*M_PI), 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], 0.5/M_PI, 1e-9);
+}
+
+void AeroElementTests::testInducedVelocityAboveWithOffset()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    SGVec3d v = el->getInducedVelocity(mp+SGVec3d(0.0, 0.5, -1.0));
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], -1.0/(4.0*M_PI*sqrt(2.0)), 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], -0.125/M_PI, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], 0.125/M_PI, 1e-9);
+}
+
+void AeroElementTests::testInducedVelocityUpstream()
+{
+    AeroElement_ptr el = new AeroElement(SGVec3d(-1., -0.5, 0.),
+                                         SGVec3d(0., -0.5, 0.),
+                                         SGVec3d(0., 0.5, 0.),
+                                         SGVec3d(-1., 0.5, 0.));
+    SGVec3d mp = el->getBoundVortexMidPoint();
+    SGVec3d v = el->getInducedVelocity(mp+SGVec3d(0.5, 0.0, 0.0));
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[0], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[1], 0.0, 1e-9);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(v[2], (1.0-sqrt(2.0))/M_PI, 1e-9);
+}

test_suite/unit_tests/FDM/testAeroElement.hxx

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2018 Edward d'Auvergne
+ *
+ * This file is part of the program FlightGear.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef _FG_AERO_ELEMENT_UNIT_TESTS_HXX
+#define _FG_AERO_ELEMENT_UNIT_TESTS_HXX
+
+
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/TestFixture.h>
+
+
+// The unit tests.
+class AeroElementTests : public CppUnit::TestFixture
+{
+    // Set up the test suite.
+    CPPUNIT_TEST_SUITE(AeroElementTests);
+    CPPUNIT_TEST(testBoundVortex);
+    CPPUNIT_TEST(testBoundVortexMidPoint);
+    CPPUNIT_TEST(testCollocationPoint);
+    CPPUNIT_TEST(testInducedVelocityAbove);
+    CPPUNIT_TEST(testInducedVelocityAboveWithOffset);
+    CPPUNIT_TEST(testInducedVelocityAtFarField);
+    CPPUNIT_TEST(testInducedVelocityOnBoundVortex);
+    //CPPUNIT_TEST(testInducedVelocityOnCollocationPoint);    // Not run in the original ctest.
+    CPPUNIT_TEST(testInducedVelocityUpstream);
+    CPPUNIT_TEST(testNormal);
+    CPPUNIT_TEST_SUITE_END();
+
+public:
+    // Set up function for each test.
+    void setUp() {}
+
+    // Clean up after each test.
+    void tearDown() {}
+
+    // The tests.
+    void testBoundVortex();
+    void testBoundVortexMidPoint();
+    void testCollocationPoint();
+    void testInducedVelocityAbove();
+    void testInducedVelocityAboveWithOffset();
+    void testInducedVelocityAtFarField();
+    void testInducedVelocityOnBoundVortex();
+    void testInducedVelocityOnCollocationPoint();
+    void testInducedVelocityUpstream();
+    void testNormal();
+};
+
+#endif  // _FG_AERO_ELEMENT_UNIT_TESTS_HXX

test_suite/unit_tests/FDM/testYASimAtmosphere.cxx

@@ -0,0 +1,44 @@
+#include "test_suite/FGTestApi/PrivateAccessorFDM.hxx"
+
+#include "testYASimAtmosphere.hxx"
+
+#include <FDM/YASim/Math.hpp>
+
+#include <simgear/debug/logstream.hxx>
+
+
+using namespace yasim;
+
+void YASimAtmosphereTests::setUp()
+{
+    a.reset(new Atmosphere());
+}
+
+
+void YASimAtmosphereTests::tearDown()
+{
+    a.reset();
+}
+
+
+void YASimAtmosphereTests::testAtmosphere()
+{
+    auto accessor = FGTestApi::PrivateAccessor::FDM::Accessor();
+
+    int numColumns = accessor.read_FDM_YASim_Atmosphere_numColumns(a);
+    int maxTableIndex = a->maxTableIndex();
+    int rows = maxTableIndex + 1;
+    const float maxDeviation = 0.0002f;
+
+    SG_LOG(SG_GENERAL, SG_INFO, "Columns = " << numColumns);
+    SG_LOG(SG_GENERAL, SG_INFO, "Rows = " << rows);
+
+    for (int alt = 0; alt <= maxTableIndex; alt++) {
+        float density = a->calcStdDensity(accessor.read_FDM_YASim_Atmosphere_data(a, alt, a->PRESSURE), accessor.read_FDM_YASim_Atmosphere_data(a, alt, a->TEMPERATURE));
+        float delta = accessor.read_FDM_YASim_Atmosphere_data(a, alt, a->DENSITY) - density;
+        SG_LOG(SG_GENERAL, SG_INFO, "alt: " << alt << ", delta: " << delta);
+        if (Math::abs(delta) > maxDeviation)
+            CPPUNIT_FAIL("Deviation above limit of 0.0002");
+    }
+    SG_LOG(SG_GENERAL, SG_INFO, "Deviation below " << maxDeviation << " for all rows.");
+}

test_suite/unit_tests/FDM/testYASimAtmosphere.hxx

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 Edward d'Auvergne
+ *
+ * This file is part of the program FlightGear.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef _FG_YASIM_ATMOSPHERE_UNIT_TESTS_HXX
+#define _FG_YASIM_ATMOSPHERE_UNIT_TESTS_HXX
+
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/TestFixture.h>
+
+#include <src/FDM/YASim/Atmosphere.hpp>
+
+
+// The unit tests.
+class YASimAtmosphereTests : public CppUnit::TestFixture
+{
+    // Set up the test suite.
+    CPPUNIT_TEST_SUITE(YASimAtmosphereTests);
+    CPPUNIT_TEST(testAtmosphere);
+    CPPUNIT_TEST_SUITE_END();
+
+public:
+    // Set up function for each test.
+    void setUp();
+
+    // Clean up after each test.
+    void tearDown();
+
+    // The tests.
+    void testAtmosphere();
+
+    // Data.
+    std::unique_ptr<yasim::Atmosphere> a;
+};
+
+#endif  // _FG_YASIM_ATMOSPHERE_UNIT_TESTS_HXX

test_suite/unit_tests/FDM/testYASimGear.cxx

@@ -0,0 +1,128 @@
+#include "testYASimGear.hxx"
+
+#include "test_suite/FGTestApi/testGlobals.hxx"
+
+#include "FDM/YASim/Gear.hpp"
+
+#include <simgear/debug/logstream.hxx>
+
+#include <sstream>
+
+
+void YASimGearTests::setUp()
+{
+    FGTestApi::setUp::initTestGlobals("");
+}
+
+void YASimGearTests::tearDown()
+{
+    FGTestApi::tearDown::shutdownTestGlobals();
+}
+
+
+void YASimGearTests::test()
+{
+    /* Check we get expected values for a particular set of inputs. */
+    
+    float ground[4] = { -0.22097, 0.00507429, -0.975263, 2.35943};
+    float wheel_pos[3] = { -0.953044, 2.20823, -2.00883};
+    yasim::GearVector wheel_axle( -0, 0.16383, -0.114715);
+    float wheel_radius = 0.261257;
+    float tyre_radius = 0.130629;
+    yasim::GearVector   compression( -0.139389, -0, 0.480178);
+    
+    float contact[3];
+    float compress_distance_vertical;
+    float compress_norm;
+    
+    bool on_ground = yasim::gearCompression(
+            ground,
+            compression,
+            wheel_pos,
+            wheel_axle,
+            wheel_radius,
+            tyre_radius,
+            [] () { return 0; },
+            
+            /* output params: */
+            contact,
+            compress_distance_vertical,
+            compress_norm
+            );
+    
+    SG_LOG( SG_GENERAL, SG_ALERT, "on_ground=" << on_ground);
+    SG_LOG( SG_GENERAL, SG_ALERT, "contact=(" << contact[0] << ", " << contact[1] << ", " << contact[1] << ")");
+    SG_LOG( SG_GENERAL, SG_ALERT, "compress_distance_vertical=" << compress_distance_vertical);
+    SG_LOG( SG_GENERAL, SG_ALERT, "compress_norm=" << compress_norm);
+    
+    double e = 0.0001;
+    CPPUNIT_ASSERT( on_ground);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( -1.1053, contact[0], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( 2.0645, contact[1], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( -2.1581, contact[2], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( 0.167955, compress_distance_vertical, e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( 0.383887, compress_norm, e);
+    
+    
+    /* Now check we get same results as old point-contact algorithm, when using
+    wheel_radius=0 and tyre_radius=0. */
+    
+    /* For this test we set gear contact point to bottom of what was the wheel,
+    so that it will be approximately in same position as earlier contact point,
+    and so slightly underground. */
+    wheel_pos[2] -= wheel_radius + tyre_radius;
+    
+    float bump_altitude_override = 0.1;
+    
+    on_ground = yasim::gearCompression(
+            ground,
+            compression,
+            wheel_pos /* contact point. */,
+            wheel_axle /* values don't matter. */,
+            0 /*wheel_radius*/,
+            0 /*tyre_radius*/,
+            [bump_altitude_override] () { return bump_altitude_override; },
+            
+            /* output params: */
+            contact,
+            compress_distance_vertical,
+            compress_norm
+            );
+    
+    float contact_old[3];
+    float compress_distance_vertical_old;
+    float compress_norm_old;
+    
+    bool on_ground_old = yasim::gearCompressionOld(
+            ground,
+            compression,
+            wheel_pos /* contact point. */,
+            [bump_altitude_override] () { return bump_altitude_override; },
+            
+            /* output params: */
+            contact_old,
+            compress_distance_vertical_old,
+            compress_norm_old
+            );
+    
+    SG_LOG( SG_GENERAL, SG_ALERT, "comparing with old algorithm.");
+    SG_LOG( SG_GENERAL, SG_ALERT, "old:");
+    SG_LOG( SG_GENERAL, SG_ALERT, "    on_ground_old=" << on_ground_old);
+    SG_LOG( SG_GENERAL, SG_ALERT, "    contact=(" << contact_old[0] << ", " << contact_old[1] << ", " << contact_old[1] << ")");
+    SG_LOG( SG_GENERAL, SG_ALERT, "    compress_distance_vertical=" << compress_distance_vertical_old);
+    SG_LOG( SG_GENERAL, SG_ALERT, "    compress_norm=" << compress_norm_old);
+    SG_LOG( SG_GENERAL, SG_ALERT, "new:");
+    SG_LOG( SG_GENERAL, SG_ALERT, "    on_ground=" << on_ground);
+    SG_LOG( SG_GENERAL, SG_ALERT, "    contact=(" << contact[0] << ", " << contact[1] << ", " << contact[1] << ")");
+    SG_LOG( SG_GENERAL, SG_ALERT, "    compress_distance_vertical=" << compress_distance_vertical);
+    SG_LOG( SG_GENERAL, SG_ALERT, "    compress_norm=" << compress_norm);
+    
+    CPPUNIT_ASSERT( on_ground);
+    CPPUNIT_ASSERT_EQUAL( on_ground_old, on_ground);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( contact_old[0], contact[0], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( contact_old[1], contact[1], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( contact_old[2], contact[2], e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( compress_distance_vertical_old, compress_distance_vertical, e);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL( compress_norm_old, compress_norm, e);
+}
+

test_suite/unit_tests/FDM/testYASimGear.hxx

@@ -0,0 +1,15 @@
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+
+struct YASimGearTests : CppUnit::TestFixture
+{
+    void setUp();
+
+    void tearDown();
+
+    void test();
+    
+    CPPUNIT_TEST_SUITE(YASimGearTests);
+    CPPUNIT_TEST(test);
+    CPPUNIT_TEST_SUITE_END();
+};

test_suite/unit_tests/FDM/test_ls_matrix.cxx

@@ -0,0 +1,155 @@
+#include "test_ls_matrix.hxx"
+
+#include <simgear/constants.h>
+#include <simgear/misc/test_macros.hxx>
+extern "C" {
+#include "src/FDM/LaRCsim/ls_matrix.h"
+}
+
+
+void LaRCSimMatrixTests::testCopyMatrix()
+{
+    int nelm = 20;
+    double **src = nr_matrix(1, nelm, 1, nelm);
+    double **dest = nr_matrix(1, nelm, 1, nelm);
+    double invmaxlong = 1.0/(double)RAND_MAX;
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            src[i][j] = 2.0 - 4.0*invmaxlong*(double) rand();
+
+    nr_copymat(src, nelm, dest);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            CPPUNIT_ASSERT_EQUAL(src[i][j], dest[i][j]);
+
+    nr_free_matrix(src, 1, nelm, 1, nelm);
+    nr_free_matrix(dest, 1, nelm, 1, nelm);
+}
+
+void LaRCSimMatrixTests::testIdentityMatrix()
+{
+    int nelm = 10;
+    double **id = nr_matrix(1, nelm, 1, nelm);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            id[i][j] = i == j ? 1.0 : 0.0;
+
+    nr_gaussj(id, nelm, 0, 0);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            CPPUNIT_ASSERT_DOUBLES_EQUAL(id[i][j], i == j ? 1.0 : 0.0, 1e-9);
+
+    nr_free_matrix(id, 1, nelm, 1, nelm);
+}
+
+void LaRCSimMatrixTests::testOrthogonalMatrix()
+{
+    int nelm = 3;
+    double **m = nr_matrix(1, nelm, 1, nelm);
+    double **inv = nr_matrix(1, nelm, 1, nelm);
+    double angle = M_PI/3.0;
+
+    m[1][1] = cos(angle);
+    m[1][2] = sin(angle);
+    m[1][3] = 0.0;
+    m[2][1] = -m[1][2];
+    m[2][2] = m[1][1];
+    m[2][3] = 0.0;
+    m[3][1] = 0.0;
+    m[3][2] = 0.0;
+    m[3][3] = 1.0;
+
+    nr_copymat(m, nelm, inv);
+    nr_gaussj(inv, nelm, 0, 0);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            CPPUNIT_ASSERT_DOUBLES_EQUAL(m[i][j], inv[j][i], 1e-9);
+
+    nr_free_matrix(m, 1, nelm, 1, nelm);
+    nr_free_matrix(inv, 1, nelm, 1, nelm);
+}
+
+void LaRCSimMatrixTests::testRandomMatrix()
+{
+    int nelm = 20;
+    double **src = nr_matrix(1, nelm, 1, nelm);
+    double **inv = nr_matrix(1, nelm, 1, nelm);
+    double **id = nr_matrix(1, nelm, 1, nelm);
+    double invmaxlong = 1.0/(double)RAND_MAX;
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            src[i][j] = 2.0 - 4.0*invmaxlong*(double) rand();
+
+    nr_copymat(src, nelm, inv);
+    nr_gaussj(inv, nelm, 0, 0);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j) {
+            id[i][j] = 0.0;
+            for (int k=1; k<=nelm; ++k)
+                id[i][j] += src[i][k]*inv[k][j];
+        }
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            CPPUNIT_ASSERT_DOUBLES_EQUAL(id[i][j], i == j ? 1.0 : 0.0, 1e-9);
+
+    nr_free_matrix(src, 1, nelm, 1, nelm);
+    nr_free_matrix(inv, 1, nelm, 1, nelm);
+    nr_free_matrix(id, 1, nelm, 1, nelm);
+}
+
+void LaRCSimMatrixTests::testSolveLinearSystem()
+{
+    int nelm = 20;
+    double **src = nr_matrix(1, nelm, 1, nelm);
+    double **inv = nr_matrix(1, nelm, 1, nelm);
+    double **rhs = nr_matrix(1, nelm, 1, 1);
+    double **sol = nr_matrix(1, nelm, 1, 1);
+    double **check = nr_matrix(1, nelm, 1, nelm);
+    double invmaxlong = 1.0/(double)RAND_MAX;
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            src[i][j] = 2.0 - 4.0*invmaxlong*(double) rand();
+
+    for (int i=1; i<=nelm; ++i) {
+        rhs[i][1] = 2.0+cos(i*M_PI/nelm);
+        sol[i][1] = rhs[i][1];
+    }
+
+    nr_copymat(src, nelm, inv);
+    nr_gaussj(inv, nelm, sol, 1);
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j) {
+            check[i][j] = 0.0;
+            for (int k=1; k<=nelm; ++k)
+                check[i][j] += src[i][k]*inv[k][j];
+        }
+
+    for (int i=1; i<=nelm; ++i)
+        for (int j=1; j<=nelm; ++j)
+            CPPUNIT_ASSERT_DOUBLES_EQUAL(check[i][j], i == j ? 1.0 : 0.0, 1e-9);
+
+    for (int i=1; i<=nelm; ++i) {
+        check[i][1] = 0.0;
+        for (int j=1; j<=nelm; ++j)
+            check[i][1] += src[i][j]*sol[j][1];
+    }
+
+    for (int i=1; i<=nelm; ++i)
+        CPPUNIT_ASSERT_DOUBLES_EQUAL(check[i][1], rhs[i][1], 1e-9);
+
+    nr_free_matrix(src, 1, nelm, 1, nelm);
+    nr_free_matrix(inv, 1, nelm, 1, nelm);
+    nr_free_matrix(check, 1, nelm, 1, nelm);
+    nr_free_matrix(rhs, 1, nelm, 1, 1);
+    nr_free_matrix(sol, 1, nelm, 1, 1);
+}

test_suite/unit_tests/FDM/test_ls_matrix.hxx

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2018 Edward d'Auvergne
+ *
+ * This file is part of the program FlightGear.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef _FG_LARCSIM_MATRIX_UNIT_TESTS_HXX
+#define _FG_LARCSIM_MATRIX_UNIT_TESTS_HXX
+
+
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/TestFixture.h>
+
+
+// The LaRCSim matrix unit tests.
+class LaRCSimMatrixTests : public CppUnit::TestFixture
+{
+    // Set up the test suite.
+    CPPUNIT_TEST_SUITE(LaRCSimMatrixTests);
+    CPPUNIT_TEST(testCopyMatrix);
+    CPPUNIT_TEST(testIdentityMatrix);
+    CPPUNIT_TEST(testOrthogonalMatrix);
+    CPPUNIT_TEST(testRandomMatrix);
+    CPPUNIT_TEST(testSolveLinearSystem);
+    CPPUNIT_TEST_SUITE_END();
+
+public:
+    // Set up function for each test.
+    void setUp() {}
+
+    // Clean up after each test.
+    void tearDown() {}
+
+    // The tests.
+    void testCopyMatrix();
+    void testIdentityMatrix();
+    void testOrthogonalMatrix();
+    void testRandomMatrix();
+    void testSolveLinearSystem();
+};
+
+#endif  // _FG_LARCSIM_MATRIX_UNIT_TESTS_HXX