TEST: Intolerant area weighted float comparison failure

lib/iris/tests/unit/experimental/regrid/test_regrid_area_weighted_rectilinear_src_and_grid.py

@@ -1,4 +1,4 @@
-# (C) British Crown Copyright 2014 - 2015, Met Office
+# (C) British Crown Copyright 2014 - 2016, Met Office
 #
 # This file is part of Iris.
 #
@@ -150,5 +150,32 @@ def test_scalar_with_overlap_above_mdtol(self):
         self.assertEqual(ma.count_masked(res.data), 1)
 
 
+class TestWrapAround(tests.IrisTest):
+    def test_float_tolerant_equality(self):
+        # Ensure that floating point numbers are treated appropriately when
+        # introducing precision difference from wrap_around.
+        source = Cube([[1]])
+        bounds = np.array([[-91, 0]], dtype='float')
+        points = bounds.mean(axis=1)
+        lon_coord = DimCoord(points, bounds=bounds, standard_name='longitude')
+        source.add_aux_coord(lon_coord, 1)
+
+        bounds = np.array([[-90, 90]], dtype='float')
+        points = bounds.mean(axis=1)
+        lat_coord = DimCoord(points, bounds=bounds, standard_name='latitude')
+        source.add_aux_coord(lat_coord, 0)
+
+        grid = Cube([[0]])
+        bounds = np.array([[270, 360]], dtype='float')
+        points = bounds.mean(axis=1)
+        lon_coord = DimCoord(points, bounds=bounds, standard_name='longitude')
+        grid.add_aux_coord(lon_coord, 1)
+        grid.add_aux_coord(lat_coord, 0)
+
+        res = regrid(source, grid)
+        # The result should be equal to the source data and NOT be masked.
+        self.assertMaskedArrayEqual(res.data, np.array([1.0]))
+
+
 if __name__ == '__main__':
     tests.main()