Add missing check for degrees in CombinationsExpr

1 files changed, 7 insertions, 1 deletions

diff --git a/polymatrix/expression/mixins/combinationsexprmixin.py b/polymatrix/expression/mixins/combinationsexprmixin.py
index ff2d201..483da96 100644
--- a/polymatrix/expression/mixins/combinationsexprmixin.py
+++ b/polymatrix/expression/mixins/combinationsexprmixin.py
@@ -1,5 +1,6 @@
 import abc
 import itertools
+import math
 from typing import Iterable
 
 from polymatrix.polymatrix.utils import multiply_polynomial
@@ -71,7 +72,12 @@ class CombinationsExprMixin(ExpressionBaseMixin):
         elif isinstance(self.degrees, tuple):
             degrees = self.degrees
 
-        # TODO: check that degrees are all integers
+        # check that degrees are all integers
+        for deg in degrees:
+            if not math.isclose(int(deg), deg):
+                raise ValueError(f"Non-integer degrees ({deg}) are not supported.")
+
+        degrees = tuple(int(d) for d in degrees)
 
         # FIXME: improve error message
         assert expr_pm.shape[1] == 1