fix storage index

Author: isuruf

sumpy/expansion/__init__.py

@@ -617,17 +617,17 @@ def get_storage_index(self, mi, order=None):
         if self.dim == 3:
             if all(isinstance(axis, int) for axis in mi):
                 if order < c - 1:
-                    return (order*(order + 1)*(order + 2))/6 + \
-                        (order + 2)*mi[0] - (mi[0]*(mi[0] + 1))/2 + mi[1]
+                    return (order*(order + 1)*(order + 2))//6 + \
+                        (order + 2)*mi[0] - (mi[0]*(mi[0] + 1))//2 + mi[1]
                 else:
-                    return (c*(c-1)*(c-2))/6 + (c * order * (2 + order - c)
-                        + mi[0]*(3 - mi[0]+2*order))/2 + mi[1]
+                    return (c*(c-1)*(c-2))//6 + (c * order * (2 + order - c)
+                        + mi[0]*(3 - mi[0]+2*order))//2 + mi[1]
             else:
                 return prim.If(prim.Comparison(order, "<", c - 1),
-                    (order*(order + 1)*(order + 2))/6
-                        + (order + 2)*mi[0] - (mi[0]*(mi[0] + 1))/2 + mi[1],
-                    (c*(c-1)*(c-2))/6 + (c * order * (2 + order - c)
-                        + mi[0]*(3 - mi[0]+2*order))/2 + mi[1]
+                    (order*(order + 1)*(order + 2))//6
+                        + (order + 2)*mi[0] - (mi[0]*(mi[0] + 1))//2 + mi[1],
+                    (c*(c-1)*(c-2))//6 + (c * order * (2 + order - c)
+                        + mi[0]*(3 - mi[0]+2*order))//2 + mi[1]
                 )
         elif self.dim == 2:
             if all(isinstance(axis, int) for axis in mi):