Handle empty arrays in gridpp::window

src/api/window.cpp

@@ -7,10 +7,21 @@ vec2 gridpp::window(const vec2& array,
     int length, gridpp::Statistic statistic, bool before,
     bool keep_missing, bool missing_edges) {
 
-    vec2 output = gridpp::init_vec2(array.size(), array[0].size(), gridpp::MV);
+    if(length <= 0) {
+        throw std::invalid_argument("Length variable must be > 0");
+    }
 
     int nY = array.size();
+    if(nY == 0) {
+        return gridpp::init_vec2(0, 0);
+    }
+
     int nX = array[0].size();
+    if(nX == 0) {
+        return gridpp::init_vec2(nY, 0);
+    }
+
+    vec2 output = gridpp::init_vec2(nY, nX, gridpp::MV);
 
     if(length % 2 == 0 && !before) {
         throw std::invalid_argument("Length variable must be an odd number");

tests/window_test.py

@@ -68,6 +68,7 @@ def test_sum_keep_missing(self):
         np.testing.assert_array_equal(output, [[0,1,3,6,9],[1,3,6,9,12],[2,5,9,12,15],[3,7,12,np.nan,np.nan],[4,9,15,18,21]])
 
     def test_edge_case(self):
+        # Check when window is beigger than array
         output = gridpp.window(self.small_inputs, 5, gridpp.Sum, False, False, False)
         np.testing.assert_array_equal(output, [[2,2],[2,2]])
 
@@ -103,8 +104,35 @@ def test_centered(self):
         output = gridpp.window(input, 3, gridpp.Sum, False, True, True)
         np.testing.assert_array_equal(output, [[np.nan, 3, np.nan, np.nan, np.nan, 12, np.nan]])
 
-if __name__ == '__main__':
-    unittest.main()
+    def test_no_times(self):
+        input = np.zeros([10, 0])
+        output = gridpp.window(input, 3, gridpp.Sum)
+        np.testing.assert_array_equal(output, input)
+
+    def test_no_cases(self):
+        input = np.zeros([0, 10], np.float32)
+        output = gridpp.window(input, 3, gridpp.Sum)
+        np.testing.assert_array_equal(output, np.zeros([0,0]))
+
+    def test_no_anything(self):
+        input = np.zeros([0, 0], np.float32)
+        output = gridpp.window(input, 3, gridpp.Sum)
+        np.testing.assert_array_equal(output, np.zeros([0,0]))
 
+    def test_invalid_length(self):
+        input = np.zeros([10, 3], np.float32)
+        for length in [0, -1]:
+            with self.assertRaises(ValueError) as e:
+                output = gridpp.window(input, length, gridpp.Sum)
 
-#if window is beigger than array () # Edge cases
+    def test_long_length(self):
+        # Check when window is beigger than array
+        output = gridpp.window([[0, 1, 2, 3]], 1001, gridpp.Sum, False, False, False)
+        np.testing.assert_array_equal(output, [[6, 6, 6, 6]])
+
+    def test_time_length_1(self):
+        output = gridpp.window([[1], [2]], 1001, gridpp.Sum, False, False, False)
+        np.testing.assert_array_equal(output, [[1], [2]])
+
+if __name__ == '__main__':
+    unittest.main()