More uniform binding of Numpy arrays (#381)

- Introduce a standard way to bind numpy arrays: py::array_t<T> and
.noconvert() on the argument
- Take py::array_t by value since it's just a small wrapper
- Update bindings

python/src/var_cluster.hpp

@@ -21,40 +21,42 @@ void define_var_cluster_finder_bindings(py::module &m) {
                  auto *ptr = new NDArray<int, 2>(self.labeled());
                  return return_image_data(ptr);
              })
-        .def("set_noiseMap",
-             [](VarClusterFinder<double> &self,
-                py::array_t<double, py::array::c_style | py::array::forcecast>
-                    noise_map) {
-                 auto noise_map_span = make_view_2d(noise_map);
-                 self.set_noiseMap(noise_map_span);
-             })
+        .def(
+            "set_noiseMap", // conversions ok
+            [](VarClusterFinder<double> &self,
+               py::array_t<double, py::array::c_style | py::array::forcecast>
+                   noise_map) {
+                auto noise_map_span = make_view_2d(noise_map);
+                self.set_noiseMap(noise_map_span);
+            },
+            py::arg("noise_map"))
         .def("set_numberOfNeighbours",
              &VarClusterFinder<double>::set_numberOfNeighbours)
         .def("set_empty_surroundingPixels",
              &VarClusterFinder<double>::set_empty_surroundingPixels)
         .def("set_peripheralThresholdFactor",
              &VarClusterFinder<double>::set_peripheralThresholdFactor)
-        .def("find_clusters",
-             [](VarClusterFinder<double> &self,
-                py::array_t<double, py::array::c_style | py::array::forcecast>
-                    img) {
-                 auto view = make_view_2d(img);
-                 self.find_clusters(view);
-             })
-        .def("find_clusters_X",
-             [](VarClusterFinder<double> &self,
-                py::array_t<double, py::array::c_style | py::array::forcecast>
-                    img) {
-                 auto img_span = make_view_2d(img);
-                 self.find_clusters_X(img_span);
-             })
-        .def("single_pass",
-             [](VarClusterFinder<double> &self,
-                py::array_t<double, py::array::c_style | py::array::forcecast>
-                    img) {
-                 auto img_span = make_view_2d(img);
-                 self.single_pass(img_span);
-             })
+        .def(
+            "find_clusters",
+            [](VarClusterFinder<double> &self, py::array_t<double> img) {
+                auto view = make_view_2d(img);
+                self.find_clusters(view);
+            },
+            py::arg("img").noconvert())
+        .def(
+            "find_clusters_X",
+            [](VarClusterFinder<double> &self, py::array_t<double> img) {
+                auto img_span = make_view_2d(img);
+                self.find_clusters_X(img_span);
+            },
+            py::arg("img").noconvert())
+        .def(
+            "single_pass",
+            [](VarClusterFinder<double> &self, py::array_t<double> img) {
+                auto img_span = make_view_2d(img);
+                self.single_pass(img_span);
+            },
+            py::arg("img").noconvert())
         .def("hits",
              [](VarClusterFinder<double> &self) {
                  auto ptr = new std::vector<VarClusterFinder<double>::Hit>(