Add warning in widening documentation

diff --git a/doc/reference.rst b/doc/reference.rst
index 4e71658..18e69c0 100644 (file)
--- a/doc/reference.rst
+++ b/doc/reference.rst
@@ -282,6 +282,8 @@ This space can be unbounded.
 
         Compute the *standard widening* of two polyhedra, à la Halbwachs.
 
+        In its current implementation, this method is slow and should not be used on large polyhedra.
+
 
 .. data:: Empty
 

diff --git a/linpy/polyhedra.py b/linpy/polyhedra.py
index 8426d32..9fdf6e7 100644 (file)
--- a/linpy/polyhedra.py
+++ b/linpy/polyhedra.py
@@ -173,6 +173,9 @@ class Polyhedron(Domain):
     def widen(self, other):
         """
         Compute the standard widening of two polyhedra, à la Halbwachs.
+
+        In its current implementation, this method is slow and should not be
+        used on large polyhedra.
         """
         if not isinstance(other, Polyhedron):
             raise ValueError('argument must be a Polyhedron instance')