Implement method Polyhedron.faces()

[linpy.git] / pypol / polyhedra.py

diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py
index 3db8f40..37f16e0 100644 (file)
--- a/pypol/polyhedra.py
+++ b/pypol/polyhedra.py
@@ -1,4 +1,3 @@
-
 import functools
 import math
 import numbers
@@ -6,6 +5,7 @@ import numbers
 from . import islhelper
 
 from .islhelper import mainctx, libisl
+from .geometry import GeometricObject, Point
 from .linexprs import Expression, Symbol, Rational
 from .domains import Domain
 
@@ -32,11 +32,7 @@ class Polyhedron(Domain):
             if inequalities is not None:
                 raise TypeError('too many arguments')
             return cls.fromstring(equalities)
-        elif isinstance(equalities, Polyhedron):
-            if inequalities is not None:
-                raise TypeError('too many arguments')
-            return equalities
-        elif isinstance(equalities, Domain):
+        elif isinstance(equalities, GeometricObject):
             if inequalities is not None:
                 raise TypeError('too many arguments')
             return equalities.aspolyhedron()
@@ -87,6 +83,19 @@ class Polyhedron(Domain):
     def aspolyhedron(self):
         return self
 
+    def __contains__(self, point):
+        if not isinstance(point, Point):
+            raise TypeError('point must be a Point instance')
+        if self.symbols != point.symbols:
+            raise ValueError('arguments must belong to the same space')
+        for equality in self.equalities:
+            if equality.subs(point.coordinates()) != 0:
+                return False
+        for inequality in self.inequalities:
+            if inequality.subs(point.coordinates()) < 0:
+                return False
+        return True
+
     def subs(self, symbol, expression=None):
         equalities = [equality.subs(symbol, expression)
             for equality in self.equalities]
@@ -233,6 +242,17 @@ class Polyhedron(Domain):
             angles[m] = angle
         return sorted(points, key=angles.get)
 
+    def faces(self):
+        vertices = self.vertices()
+        faces = []
+        for constraint in self.constraints:
+            face = []
+            for vertex in vertices:
+                if constraint.subs(vertex.coordinates()) == 0:
+                    face.append(vertex)
+            faces.append(face)
+        return faces
+
     def plot(self):
         import matplotlib.pyplot as plt
         from matplotlib.path import Path