Merge pull request #3831 from lanzagar/bincount

[FIX] util: Fix bincount for object arrays

Orange/statistics/util.py

@@ -82,7 +82,7 @@ def sparse_implicit_zero_weights(x, weights):
 def bincount(x, weights=None, max_val=None, minlength=0):
     """Return counts of values in array X.
 
-    Works kind of like np.bincount(), except that it also supports floating
+    Works kind of like np.bincount(), except that it also supports
     arrays with nans.
 
     Parameters
@@ -132,8 +132,8 @@ def bincount(x, weights=None, max_val=None, minlength=0):
 
         x = x.data
 
-    x = np.asanyarray(x)
-    if x.dtype.kind == 'f' and bn.anynan(x):
+    x = np.asanyarray(x, dtype=float)
+    if bn.anynan(x):
         nonnan = ~np.isnan(x)
         x = x[nonnan]
         if weights is not None:

Orange/tests/test_statistics.py

@@ -517,6 +517,13 @@ def test_count_nans(self, array):
 
         np.testing.assert_equal(bincount(x)[1], expected)
 
+    # object arrays cannot be converted to sparse, so test only for dense
+    def test_count_nans_objectarray(self):
+        x = np.array([0, 0, 1, 2, np.nan, 2], dtype=object)
+        expected = 1
+
+        np.testing.assert_equal(bincount(x)[1], expected)
+
     @dense_sparse
     def test_adds_empty_bins(self, array):
         x = array([0, 1, 3, 5])