Added some docs

[linpy.git] / pypol / domains.py

diff --git a/pypol/domains.py b/pypol/domains.py
index 23c21af..1c400bd 100644 (file)
--- a/pypol/domains.py
+++ b/pypol/domains.py
@@ -445,37 +445,41 @@ class Domain(GeometricObject):
         return sorted(points, key=angles.get)
 
     def faces(self):
-        vertices = self.vertices()
+    """
+    Returns the vertices of the faces of a polyhedra.
+    """
         faces = []
-        for constraint in self.constraints:
-            face = []
-            for vertex in vertices:
-                if constraint.subs(vertex.coordinates()) == 0:
-                    face.append(vertex)
-            faces.append(face)
+        for polyhedron in self.polyhedra:
+            vertices = polyhedron.vertices()
+            for constraint in polyhedron.constraints:
+                face = []
+                for vertex in vertices:
+                    if constraint.subs(vertex.coordinates()) == 0:
+                        face.append(vertex)
+                if len(face) >= 3:
+                    faces.append(face)
         return faces
 
     def _plot_2d(self, plot=None, **kwargs):
         import matplotlib.pyplot as plt
         from matplotlib.patches import Polygon
+        if plot is None:
+            fig = plt.figure()
+            plot = fig.add_subplot(1, 1, 1)
+        xmin, xmax = plot.get_xlim()
+        ymin, ymax = plot.get_ylim()
         for polyhedron in self.polyhedra:
             vertices = polyhedron._sort_polygon_2d(polyhedron.vertices())
             xys = [tuple(vertex.values()) for vertex in vertices]
-            if plot is None:
-                fig = plt.figure()
-                plot = fig.add_subplot(1, 1, 1)
-            xmin, xmax = plot.get_xlim()
-            ymin, ymax = plot.get_xlim()
             xs, ys = zip(*xys)
             xmin, xmax = min(xmin, float(min(xs))), max(xmax, float(max(xs)))
             ymin, ymax = min(ymin, float(min(ys))), max(ymax, float(max(ys)))
-            plot.set_xlim(xmin, xmax)
-            plot.set_ylim(ymin, ymax)
             plot.add_patch(Polygon(xys, closed=True, **kwargs))
+        plot.set_xlim(xmin, xmax)
+        plot.set_ylim(ymin, ymax)
         return plot
 
     def _plot_3d(self, plot=None, **kwargs):
-        from .polyhedra import Polyhedron
         import matplotlib.pyplot as plt
         from mpl_toolkits.mplot3d import Axes3D
         from mpl_toolkits.mplot3d.art3d import Poly3DCollection
@@ -485,33 +489,33 @@ class Domain(GeometricObject):
         else:
             axes = plot
         xmin, xmax = axes.get_xlim()
-        ymin, ymax = axes.get_xlim()
-        zmin, zmax = axes.get_xlim()
+        ymin, ymax = axes.get_ylim()
+        zmin, zmax = axes.get_zlim()
         poly_xyzs = []
-        for polyhedron in self.polyhedra:
-            for vertices in polyhedron.faces():
-                if len(vertices) == 0:
-                    continue
-                vertices = Polyhedron._sort_polygon_3d(vertices)
-                vertices.append(vertices[0])
-                face_xyzs = [tuple(vertex.values()) for vertex in vertices]
-                xs, ys, zs = zip(*face_xyzs)
-                xmin, xmax = min(xmin, float(min(xs))), max(xmax, float(max(xs)))
-                ymin, ymax = min(ymin, float(min(ys))), max(ymax, float(max(ys)))
-                zmin, zmax = min(zmin, float(min(zs))), max(zmax, float(max(zs)))
-                poly_xyzs.append(face_xyzs)
-            collection = Poly3DCollection(poly_xyzs, **kwargs)
-            axes.add_collection3d(collection)
-            axes.set_xlim(xmin, xmax)
-            axes.set_ylim(ymin, ymax)
-            axes.set_zlim(zmin, zmax)
+        for vertices in self.faces():
+            vertices = self._sort_polygon_3d(vertices)
+            vertices.append(vertices[0])
+            face_xyzs = [tuple(vertex.values()) for vertex in vertices]
+            xs, ys, zs = zip(*face_xyzs)
+            xmin, xmax = min(xmin, float(min(xs))), max(xmax, float(max(xs)))
+            ymin, ymax = min(ymin, float(min(ys))), max(ymax, float(max(ys)))
+            zmin, zmax = min(zmin, float(min(zs))), max(zmax, float(max(zs)))
+            poly_xyzs.append(face_xyzs)
+        collection = Poly3DCollection(poly_xyzs, **kwargs)
+        axes.add_collection3d(collection)
+        axes.set_xlim(xmin, xmax)
+        axes.set_ylim(ymin, ymax)
+        axes.set_zlim(zmin, zmax)
         return axes
 
+
     def plot(self, plot=None, **kwargs):
         """
         Display plot of this set.
         """
-        if self.dimension == 2:
+        if not self.isbounded():
+            raise ValueError('domain must be bounded')
+        elif self.dimension == 2:
             return self._plot_2d(plot=plot, **kwargs)
         elif self.dimension == 3:
             return self._plot_3d(plot=plot, **kwargs)
@@ -525,6 +529,9 @@ class Domain(GeometricObject):
         return False
 
     def subs(self, symbol, expression=None):
+    """
+    Subsitute the given value into an expression and return the resulting expression.
+    """
         polyhedra = [polyhedron.subs(symbol, expression)
             for polyhedron in self.polyhedra]
         return Domain(*polyhedra)