Add method Polyhedron.convex_union()
[linpy.git] / linpy / polyhedra.py
index 31b64b1..50af053 100644 (file)
@@ -144,6 +144,15 @@ class Polyhedron(Domain):
     def aspolyhedron(self):
         return self
 
     def aspolyhedron(self):
         return self
 
+    def convex_union(self, *others):
+        """
+        Return the convex union of two or more polyhedra.
+        """
+        for other in others:
+            if not isinstance(other, Polyhedron):
+                raise TypeError('arguments must be Polyhedron instances')
+        return Polyhedron(self.union(*others))
+
     def __contains__(self, point):
         if not isinstance(point, Point):
             raise TypeError('point must be a Point instance')
     def __contains__(self, point):
         if not isinstance(point, Point):
             raise TypeError('point must be a Point instance')
@@ -178,7 +187,7 @@ class Polyhedron(Domain):
         used on large polyhedra.
         """
         if not isinstance(other, Polyhedron):
         used on large polyhedra.
         """
         if not isinstance(other, Polyhedron):
-            raise ValueError('argument must be a Polyhedron instance')
+            raise TypeError('argument must be a Polyhedron instance')
         inequalities1 = self._asinequalities()
         inequalities2 = other._asinequalities()
         inequalities = []
         inequalities1 = self._asinequalities()
         inequalities2 = other._asinequalities()
         inequalities = []
@@ -399,15 +408,15 @@ def Ne(left, right):
     return ~Eq(left, right)
 
 @_polymorphic
     return ~Eq(left, right)
 
 @_polymorphic
-def Gt(left, right):
+def Ge(left, right):
     """
     """
-    Create the polyhedron with constraints expr1 > expr2 > expr3 ...
+    Create the polyhedron with constraints expr1 >= expr2 >= expr3 ...
     """
     """
-    return Polyhedron([], [left - right - 1])
+    return Polyhedron([], [left - right])
 
 @_polymorphic
 
 @_polymorphic
-def Ge(left, right):
+def Gt(left, right):
     """
     """
-    Create the polyhedron with constraints expr1 >= expr2 >= expr3 ...
+    Create the polyhedron with constraints expr1 > expr2 > expr3 ...
     """
     """
-    return Polyhedron([], [left - right])
+    return Polyhedron([], [left - right - 1])