Show distance column in solution only when required

src/vroom/input/input.py

@@ -31,6 +31,7 @@ class Input(_vroom.Input):
     """
 
     _geometry: bool = False
+    _distances: bool = False
 
     def __init__(
         self,
@@ -308,6 +309,7 @@ def set_distances_matrix(
         if not isinstance(matrix_input, _vroom.Matrix):
             matrix_input = _vroom.Matrix(numpy.asarray(matrix_input, dtype="uint32"))
         self._set_distances_matrix(profile, matrix_input)
+        self._distances = True
 
     def set_costs_matrix(
         self,
@@ -341,4 +343,5 @@ def solve(
             )
         )
         solution._geometry = self._geometry
+        solution._distances = self._distances
         return solution

src/vroom/solution/solution.py

@@ -24,6 +24,7 @@ class Solution(_vroom.Solution):
     """
 
     _geometry: bool = False
+    _distances: bool = False
 
     @property
     def routes(self) -> pandas.DataFrame:
@@ -58,6 +59,8 @@ def routes(self) -> pandas.DataFrame:
             The identifier for the task that was performed.
         description:
             Text description provided to this step.
+        distance:
+            Total route distance.
         """
         array = numpy.asarray(self._routes_numpy())
         frame = pandas.DataFrame(
@@ -84,15 +87,15 @@ def routes(self) -> pandas.DataFrame:
                 del frame[column]
             else:
                 frame.loc[frame[column] == NA_SUBSTITUTE, column] = pandas.NA
-        if self._geometry:
+        if self._geometry or self._distances:
             frame["distance"] = array["distance"]
         return frame
 
     def to_dict(self) -> Dict[str, Any]:
         """Convert solution into VROOM compatible dictionary."""
         stream = io.StringIO()
         with redirect_stdout(stream):
-            if self._geometry:
+            if self._geometry or self._distances:
                 self._geometry_solution_json()
             else:
                 self._solution_json()
@@ -102,7 +105,7 @@ def to_json(self, filepath: Union[str, Path]) -> None:
         """Store solution into VROOM compatible JSON file."""
         with open(filepath, "w") as handler:
             with redirect_stdout(handler):
-                if self._geometry:
+                if self._geometry or self._distances:
                     self._geometry_solution_json()
                 else:
                     self._solution_json()

test/test_libvroom_examples.py

@@ -15,6 +15,13 @@ def test_example_with_custom_matrix():
                       [197, 2256, 0, 1102],
                       [1299, 3153, 1102, 0]],
     )
+    problem_instance.set_distances_matrix(
+        profile="car",
+        matrix_input=[[0, 21040, 1970, 12990],
+                      [21030, 0, 22550, 31520],
+                      [1970, 22560, 0, 11020],
+                      [12990, 31530, 11020, 0]],
+    )
     problem_instance.add_vehicle([vroom.Vehicle(7, start=0, end=0),
                                   vroom.Vehicle(8, start=2, end=2)])
     problem_instance.add_job([vroom.Job(id=1414, location=0),
@@ -37,3 +44,5 @@ def test_example_with_custom_matrix():
     assert numpy.all(routes.arrival == [0, 2104, 4207, 4207,
                                         0, 1102, 2204, 2204])
     assert numpy.all(routes.location_index == [0, 1, 0, 0, 2, 3, 2, 2])
+    assert numpy.all(routes.distance == [0, 21040, 42070, 42070,
+                                         0, 11020, 22040, 22040])