some fixes

Author: Juan Orduz

pymc_bart/tree.py

@@ -309,9 +309,19 @@ def _traverse_tree(
                 )
                 if excluded is not None and idx_split_variable in excluded:
                     prop_nvalue_left = self.get_node(left_node_index).nvalue / node.nvalue
-                    stack.append((left_node_index, weights * prop_nvalue_left, idx_split_variable))
                     stack.append(
-                        (right_node_index, weights * (1 - prop_nvalue_left), idx_split_variable)
+                        (
+                            left_node_index,
+                            (weights * prop_nvalue_left).astype(np.float64),
+                            idx_split_variable,
+                        )
+                    )
+                    stack.append(
+                        (
+                            right_node_index,
+                            (weights * (1 - prop_nvalue_left)).astype(np.float64),
+                            idx_split_variable,
+                        )
                     )
                 else:
                     to_left = (

pymc_bart/utils.py

@@ -848,7 +848,7 @@ def compute_variable_importance(  # noqa: PLR0915 PLR0912
         idxs = np.argsort(
             idata["sample_stats"]["variable_inclusion"].mean(("chain", "draw")).values
         )
-        subsets = [idxs[:-i].tolist() for i in range(1, len(idxs))]
+        subsets: list[list[int]] = [list(idxs[:-i]) for i in range(1, len(idxs))]
         subsets.append(None)  # type: ignore
 
         if method == "backward_VI":