Resolve comments

src/pygambit/game.pxi

@@ -19,6 +19,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #
+import fractions
 import itertools
 import pathlib
 
@@ -336,36 +337,31 @@ class Game:
         g.title = title
         return g
 
-    def to_arrays(self) -> typing.List[np.array]:
-        """Reverse function to from_arrays:
-
-        To_arrays, for a given game, generates players’ payoff tables represented as numpy arrays.
-        The number of produced arrays is equal to the number of players.
+    def to_arrays(self, dtype=fractions.Fraction) -> typing.List[np.array]:
+        """Generate the payoff tables for players represented as numpy arrays.
+        Parameters
+        ----------
+        dtype : type
+            The desired datatype of the payoff values
 
         Returns
         -------
-        list of np.arrays
+        list of np.array
 
-        Raises
-        ------
-        UndefinedOperationError
-            If the game does not have a tree representation.
+        See Also
+        --------
+        from_arrays : Create game from list-like of array-like
         """
         arrays = []
 
-        if self.is_tree:
-            raise UndefinedOperationError(
-                "Operation only defined for games with a strategic representation"
-                )
-
-        if len(self.players) == 0:
-            raise RuntimeError("There are no players in the game")
+        if dtype != fractions.Fraction and dtype != float:
+            raise NotImplementedError("Unsupported type of payoff")
 
         shape = tuple(len(player.strategies) for player in self.players)
         for player in self.players:
-            array = np.zeros(shape=shape)
+            array = np.zeros(shape=shape, dtype=object)
             for profile in itertools.product(*(range(s) for s in shape)):
-                array[profile] = self[profile][player]
+                array[profile] = dtype(self[profile][player])
             arrays.append(array)
         return arrays
 

tests/test_game.py

@@ -1,3 +1,5 @@
+from fractions import Fraction
+
 import numpy as np
 import pygambit as gbt
 import pytest
@@ -13,22 +15,24 @@ def test_from_arrays():
     assert len(game.players[1].strategies) == 2
 
 
-def test_extensive_form_to_arrays():
-    game = gbt.Game.new_tree()
-    with pytest.raises(ValueError):
-        _ = game.to_arrays()
-
-
 def test_empty_array_to_arrays():
     game = gbt.Game.from_arrays([])
     a = game.to_arrays()
     assert len(a) == 1
     assert (a[0] == np.array([])).all()
 
 
-def test_different_num_representations_to_arrays():
+def test_different_num_representations_to_arrays_fraction():
     game = gbt.Game.from_arrays([1, 2 / 1, "6/2", 0.25, ".99"])
     A = game.to_arrays()[0]
+    correct_output = [Fraction(1, 1), Fraction(2, 1), Fraction(3, 1), Fraction(1, 4),
+                      Fraction(99, 100)]
+    assert (correct_output == A).all()
+
+
+def test_different_num_representations_to_arrays_float():
+    game = gbt.Game.from_arrays([1, 2 / 1, "6/2", 0.25, ".99"])
+    A = game.to_arrays(dtype=float)[0]
     correct_output = [1.0, 2.0, 3.0, 0.25, 0.99]
     assert (correct_output == A).all()