Minor improvements in diamonds.py example

[linpy.git] / pypol / polyhedra.py

diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py
index 6b5f9ab..aabe0fd 100644 (file)
--- a/pypol/polyhedra.py
+++ b/pypol/polyhedra.py
@@ -71,9 +71,15 @@ class Polyhedron(Domain):
         return self,
 
     def disjoint(self):
+        """
+        Return this set as disjoint.
+        """
         return self
 
     def isuniverse(self):
+        """
+        Return true if this set is the Universe set.
+        """
         islbset = self._toislbasicset(self.equalities, self.inequalities,
             self.symbols)
         universe = bool(libisl.isl_basic_set_is_universe(islbset))
@@ -81,6 +87,9 @@ class Polyhedron(Domain):
         return universe
 
     def aspolyhedron(self):
+        """
+        Return polyhedral hull of this set.
+        """
         return self
 
     def __contains__(self, point):
@@ -263,7 +272,7 @@ class Polyhedron(Domain):
         for m in points[1:]:
             om = Vector(o, m)
             normprod = norm_oa * om.norm()
-            cosinus = oa.dot(om) / normprod
+            cosinus = max(oa.dot(om) / normprod, -1.)
             sinus = u.dot(oa.cross(om)) / normprod
             angle = math.acos(cosinus)
             angle = math.copysign(angle, sinus)
@@ -281,44 +290,65 @@ class Polyhedron(Domain):
             faces.append(face)
         return faces
 
-    def plot(self):
+    def _plot_2d(self, plot=None, **kwargs):
         import matplotlib.pyplot as plt
-        from matplotlib.path import Path
-        import matplotlib.patches as patches
-
-        if len(self.symbols)> 3:
-            raise TypeError
-
-        elif len(self.symbols) == 2:
-            verts = self.vertices()
-            points = []
-            codes = [Path.MOVETO]
-            for vert in verts:
-                pairs = ()
-                for sym in sorted(vert, key=Symbol.sortkey):
-                    num = vert.get(sym)
-                    pairs = pairs + (num,)
-                points.append(pairs)
-            points.append((0.0, 0.0))
-            num = len(points)
-            while num > 2:
-                codes.append(Path.LINETO)
-                num = num - 1
-            else:
-                codes.append(Path.CLOSEPOLY)
-            path = Path(points, codes)
+        from matplotlib.patches import Polygon
+        vertices = self._sort_polygon_2d(self.vertices())
+        xys = [tuple(vertex.values()) for vertex in vertices]
+        if plot is None:
             fig = plt.figure()
-            ax = fig.add_subplot(111)
-            patch = patches.PathPatch(path, facecolor='blue', lw=2)
-            ax.add_patch(patch)
-            ax.set_xlim(-5,5)
-            ax.set_ylim(-5,5)
-            plt.show()
-
-        elif len(self.symbols)==3:
-            return 0
-
-        return points
+            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))
+        return plot
+
+    def _plot_3d(self, plot=None, **kwargs):
+        import matplotlib.pyplot as plt
+        from mpl_toolkits.mplot3d import Axes3D
+        from mpl_toolkits.mplot3d.art3d import Poly3DCollection
+        if plot is None:
+            fig = plt.figure()
+            axes = Axes3D(fig)
+        else:
+            axes = plot
+        xmin, xmax = axes.get_xlim()
+        ymin, ymax = axes.get_xlim()
+        zmin, zmax = axes.get_xlim()
+        poly_xyzs = []
+        for vertices in self.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)
+        return axes
+
+    def plot(self, plot=None, **kwargs):
+        """
+        Display 3D plot of set.
+        """
+        if self.dimension == 2:
+            return self._plot_2d(plot=plot, **kwargs)
+        elif self.dimension == 3:
+            return self._plot_3d(plot=plot, **kwargs)
+        else:
+            raise ValueError('polyhedron must be 2 or 3-dimensional')
 
 
 def _polymorphic(func):
@@ -341,26 +371,44 @@ def _polymorphic(func):
 
 @_polymorphic
 def Lt(left, right):
+    """
+    Return true if the first set is less than the second.
+    """
     return Polyhedron([], [right - left - 1])
 
 @_polymorphic
 def Le(left, right):
+    """
+    Return true the first set is less than or equal to the second.
+    """
     return Polyhedron([], [right - left])
 
 @_polymorphic
 def Eq(left, right):
+    """
+    Return true if the sets are equal.
+    """
     return Polyhedron([left - right], [])
 
 @_polymorphic
 def Ne(left, right):
+    """
+    Return true if the sets are NOT equal.
+    """
     return ~Eq(left, right)
 
 @_polymorphic
 def Gt(left, right):
+    """
+    Return true if the first set is greater than the second set.
+    """
     return Polyhedron([], [left - right - 1])
 
 @_polymorphic
 def Ge(left, right):
+    """
+    Return true if the first set is greater than or equal the second set.
+    """
     return Polyhedron([], [left - right])