make curve and curves pickleable

README.md

@@ -2,7 +2,7 @@
 A fast, scalable and light-weight C++ Fréchet distance library, exposed to python and focused on (k,l)-clustering of polygonal curves.
 
 ### DISTANCE FUNCTION FOR CLUSTERING CAN BE CHOSEN (heuristic in case of DTW)
-### NOW WITH OPTIMIZED CLUSTER CENTERS
+### CURVE AND CURVES CAN NOW BE PICKLED
 
 ## Ingredients
 `import Fred as fred`

setup.py

@@ -80,7 +80,7 @@ def build_extension(self, ext):
 
 setup(
     name='Fred-Frechet',
-    version='1.12.3',
+    version='1.12.4',
     author='Dennis Rohde',
     author_email='[email protected]',
     description='A fast, scalable and light-weight C++ Fréchet distance library, exposed to python and focused on (k,l)-clustering of polygonal curves.',

src/clustering.cpp

@@ -53,7 +53,7 @@ void Clustering_Result::compute_assignment(const Curves &in, const bool consecut
     if (consecutive_call and in.size() == distances.size()) {
         for (curve_number_t i = 0; i < in.size(); ++i) assignment[_nearest_center(i, in, simplifications, center_indices, distances, distance_func)].push_back(i);
     } else {
-        distances = Distance_Matrix(in.size(), centers.size());
+        if (use_distance_matrix) distances = Distance_Matrix(in.size(), centers.size());
         auto ncenter_indices = Curve_Numbers(centers.size());
         std::iota(ncenter_indices.begin(), ncenter_indices.end(), 0);
         for (curve_number_t i = 0; i < in.size(); ++i) 

src/fred_python_wrapper.cpp

@@ -106,6 +106,15 @@ PYBIND11_MODULE(backend, m) {
         .def("__str__", &Curve::str)
         .def("__iter__", [](Curve &v) { return py::make_iterator(v.begin(), v.end()); }, py::keep_alive<0, 1>())
         .def("__repr__", &Curve::repr)
+        .def(py::pickle(
+            [](const Curve &c) {
+                return py::make_tuple(c.as_ndarray(), c.get_name());
+            },
+            [](py::tuple t) {
+                const auto coords = t[0].cast<py::array_t<coordinate_t>>();
+                const auto name = t[1].cast<std::string>();
+                return Curve(coords, name);
+            } ))
     ;
 
     py::class_<Curves>(m, "Curves")
@@ -122,6 +131,24 @@ PYBIND11_MODULE(backend, m) {
         .def("__repr__", &Curves::repr)
         .def_property_readonly("values", &Curves::as_ndarray)
         .def_property_readonly("dimensions", &Curves::dimensions)
+        .def(py::pickle(
+            [](const Curves &c) {
+                py::list l;
+                for (const Curve &elem : c) {
+                    l.append(py::make_tuple(elem.as_ndarray(), elem.get_name()));
+                }
+                return l;
+            },
+            [](py::list l) {
+                Curves result;
+                for (const auto &elem : l) {
+                    const auto t = elem.cast<py::tuple>();
+                    const auto coords = t[0].cast<py::array_t<coordinate_t>>();
+                    const auto name = t[1].cast<std::string>();
+                    result.push_back(Curve(coords, name));
+                }
+                return result;
+            } ))
     ;
 
     py::class_<fc::Distance>(m, "Continuous_Frechet_Distance")