Bug fix in function evaluation

mxfusion/components/functions/function_evaluation.py

@@ -89,7 +89,7 @@ def eval_RT(self, F, always_return_tuple=False, **input_kws):
                         results.append(r)
                     if isinstance(results[0], (list, tuple)):
                         # if the function has multiple output variables.
-                        results = [F.concat([r[i] for r in results], dim=0) for
+                        results = [F.concat(*[r[i] for r in results], dim=0) for
                                    i in range(len(results[0]))]
                     else:
                         results = F.concat(*results, dim=0)