Add scattering analysis unit test

src/CMakeLists.txt

@@ -84,6 +84,7 @@ set(tsts
     ${CMAKE_SOURCE_DIR}/src/molecule_test.h
     ${CMAKE_SOURCE_DIR}/src/particle_test.h
     ${CMAKE_SOURCE_DIR}/src/potentials_test.h
+    ${CMAKE_SOURCE_DIR}/src/scatter_test.h
     ${CMAKE_SOURCE_DIR}/src/space_test.h
     ${CMAKE_SOURCE_DIR}/src/tensor_test.h
     )

src/scatter_test.h

@@ -0,0 +1,41 @@
+#include "analysis.h"
+#include "io.h"
+
+namespace Faunus {
+namespace Scatter {
+
+using doctest::Approx;
+
+double box = 80;
+const std::vector<Point> positions = {
+    {10, 20, 30},  {-32, 19, 1},  {34, -2, 23}, {0, 0, 1},     {25, 0, -12},
+    {-6, -4, -29}, {-12, 23, -3}, {3, 1, -4},   {-31, 29, -20}}; // random position vector
+
+TEST_CASE_TEMPLATE("[Faunus] StructureFactorPBC", T, StructureFactorPBC<float>) {
+    size_t cnt = 0;
+    std::vector<float> result = {0.0785, 1.48621,  0.1111, 0.567279, 0.136,  1.39515,
+                                 0.1571, 0.730579, 0.2221, 0.701547, 0.2721, 0.692064};
+    T scatter(2);
+    scatter.sample(positions, box);
+    for (auto [q, S] : scatter.getSampling()) {
+        CHECK(q == Approx(result[cnt++]));
+        CHECK(S == Approx(result[cnt++]));
+    }
+    CHECK(cnt == result.size());
+}
+
+TEST_CASE("[Faunus] StructureFactorIPBC") {
+    size_t cnt = 0;
+    std::vector<double> result = {0.0785, 0.384363, 0.1111, 1.51652, 0.136,  1.18027,
+                                  0.1571, 1.40662,  0.2221, 2.06042, 0.2721, 1.53482};
+    StructureFactorIPBC scatter(2);
+    scatter.sample(positions, box);
+    for (auto [q, S] : scatter.getSampling()) {
+        CHECK(q == Approx(result[cnt++]));
+        CHECK(S == Approx(result[cnt++]));
+    }
+    CHECK(cnt == result.size());
+}
+
+} // namespace Scatter
+} // namespace Faunus

src/unittests.cpp

@@ -26,6 +26,7 @@
 #include "space_test.h"
 #include "tensor_test.h"
 #include "externalpotential_test.h"
+#include "scatter_test.h"
 
 #include "mpicontroller.h"
 #include "auxiliary.h"