Merge pull request #37 from SylvainCorlay/shape-comparison

Add shape comparison operators

Author: SylvainCorlay

include/xtensor-python/pybuffer_adaptor.hpp

@@ -11,14 +11,14 @@
 
 #include <cstddef>
 #include <iterator>
+#include <algorithm>
 
 namespace xt
 {
 
     template <class T>
     class pybuffer_adaptor
     {
-
     public:
 
         using value_type = T;
@@ -72,6 +72,24 @@ namespace xt
         size_type m_size;
     };
 
+    template<class T>
+    bool operator==(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
+    template<class T>
+    bool operator<(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
+    template<class T>
+    bool operator!=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
+    template<class T>
+    bool operator>(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
+    template<class T>
+    bool operator<=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
+    template<class T>
+    bool operator>=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y);
+
     template <std::size_t N>
     class pystrides_iterator;
 
@@ -110,7 +128,7 @@ namespace xt
         const_pointer p_data;
         size_type m_size;
     };
-    
+
     /***********************************
      * pybuffer_adaptor implementation *
      ***********************************/
@@ -240,7 +258,43 @@ namespace xt
     {
         return rend();
     }
-    
+ 
+    template<class T>
+    inline bool operator==(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return (x.size() == y.size() && std::equal(x.begin(), x.end(), y.begin()));
+    }
+
+    template<class T>
+    inline bool operator<(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return std::lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());
+    }
+
+    template<class T>
+    inline bool operator!=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return !(x == y);
+    }
+
+    template<class T>
+    inline bool operator>(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return y < x;
+    }
+
+    template<class T>
+    inline bool operator<=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return !(y < x);
+    }
+
+    template<class T>
+    inline bool operator>=(const pybuffer_adaptor<T>& x, const pybuffer_adaptor<T>& y)
+    {
+        return !(x < y);
+    }
+
     /*************************************
      * pystrides_iterator implementation *
      *************************************/

test/main.cpp

@@ -51,17 +51,21 @@ PYBIND11_PLUGIN(xtensor_python_test)
 
     py::module m("xtensor_python_test", "Test module for xtensor python bindings");
 
-    m.def("example1", example1, "");
-    m.def("example2", example2, "");
+    m.def("example1", example1);
+    m.def("example2", example2);
 
-    m.def("readme_example1", readme_example1, "");
-    m.def("readme_example2", xt::pyvectorize(readme_example2), "");
+    m.def("readme_example1", readme_example1);
+    m.def("readme_example2", xt::pyvectorize(readme_example2));
 
-    m.def("vectorize_example1", xt::pyvectorize(add), "");
+    m.def("vectorize_example1", xt::pyvectorize(add));
 
-    m.def("rect_to_polar", [](xt::pyarray<complex_t> const& a) {
-            return py::make_tuple(xt::pyvectorize([](complex_t x) { return std::abs(x); })(a),
-                                  xt::pyvectorize([](complex_t x) { return std::arg(x); })(a));
+    m.def("rect_to_polar", [](const xt::pyarray<complex_t>& a) {
+        return py::make_tuple(xt::pyvectorize([](complex_t x) { return std::abs(x); })(a),
+                              xt::pyvectorize([](complex_t x) { return std::arg(x); })(a));
+    });
+
+    m.def("compare_shapes", [](const xt::pyarray<double>& a, const xt::pyarray<double>& b) {
+        return a.shape() == b.shape();
     });
 
     return m.ptr();

test/test_pyarray.py

@@ -50,3 +50,10 @@ def test_rect_to_polar(self):
         z = xt.rect_to_polar(x[::2]);
         np.testing.assert_allclose(z, (np.ones(5, dtype=float), np.zeros(5, dtype=float)), 1e-5)
 
+    def test_shape_comparison(self):
+        x = np.ones([4, 4])
+        y = np.ones([5, 5])
+        z = np.zeros([4, 4])
+        self.assertFalse(xt.compare_shapes(x, y))
+        self.assertTrue(xt.compare_shapes(x, z))
+