Test node permutation via bin map

Author: nspope

python/tests/test_lowlevel.py

@@ -4259,6 +4259,15 @@ def test_output_dims(self):
         coal = self.pair_coalescence_counts(ts, span_normalise=True)
         assert coal.shape == dim
 
+    def test_node_shuffle(self):
+        rng = np.random.default_rng(1024)
+        ts = self.example_ts()
+        coal = self.pair_coalescence_counts(ts)
+        node_bin_map = np.arange(ts.get_num_nodes(), dtype=np.int32)
+        rng.shuffle(node_bin_map)
+        coal_shuffle = self.pair_coalescence_counts(ts, node_bin_map=node_bin_map)
+        np.testing.assert_allclose(coal_shuffle[..., node_bin_map], coal)
+
     @pytest.mark.parametrize("bad_node", [-1, -2, 1000])
     def test_c_tsk_err_node_out_of_bounds(self, bad_node):
         ts = self.example_ts()