Add plot method

diff --git a/examples/squares.py b/examples/squares.py
index 4389d87..e00821e 100755 (executable)
--- a/examples/squares.py
+++ b/examples/squares.py
@@ -9,8 +9,11 @@ sq2 = Le(2, x) & Le(x, 4) & Le(2, y) & Le(y, 4)
 sq3 = Le(0, x) & Le(x, 3) & Le(0, y) & Le(y, 3)
 sq4 = Le(1, x) & Le(x, 2) & Le(1, y) & Le(y, 2)
 sq5 = Le(1, x) & Le(x, 2) & Le(1, y)
-sq6 = Le(1, x) & Le(x, 2) & Le(1, y) & Eq(y, 3)
+sq6 = Le(1, x) & Le(x, 2) & Le(1, y) & Le(y, 3)
 sq7 = Le(0, x) & Le(x, 2) & Le(0, y) & Eq(z, 2) & Le(a, 3)
+p = Le(2*x+1, y) & Le(-2*x-1, y) & Le(y, 1)
+
+
 universe = Polyhedron([])
 q = sq1 - sq2
 e = Empty
@@ -69,3 +72,7 @@ print()
 print('sq1 has {} parameters'.format(sq1.num_parameters()))
 print()
 print('does sq1 constraints involve x?', sq1.involves_dims([x]))
+print()
+print('the verticies for s are:', p.vertices())
+print()
+print(p.plot())

diff --git a/pypol/domains.py b/pypol/domains.py
index 44c38e7..375be85 100644 (file)
--- a/pypol/domains.py
+++ b/pypol/domains.py
@@ -268,24 +268,20 @@ class Domain:
         points = {}
         num = 0
         vertices_points = []
-        symbols = list(self.symbols)
         for vertex in vertices:
-            expr = libisl.isl_vertex_get_expr(vertex); #make vertices a bset
             if islhelper.isl_version < '0.13':
+                expr = libisl.isl_vertex_get_expr(vertex)
                 constraints = islhelper.isl_basic_set_constraints(expr) #get bset constraints
-                for dim in symbols:
-                    index = symbols.index(dim)
-                    for c in constraints: #for each constraint 
-                        constant = libisl.isl_constraint_get_constant_val(c) #get contant value
+                for index, dim in enumerate(self.symbols):
+                    for c in constraints: #for each constraint
+                        constant = libisl.isl_constraint_get_constant_val(c) #get constant value
                         constant = islhelper.isl_val_to_int(constant)
                         coefficient = libisl.isl_constraint_get_coefficient_val(c,libisl.isl_dim_set, index)
                         coefficient = islhelper.isl_val_to_int(coefficient) #get coefficient
                         if coefficient != 0:
-                            num = Fraction(constant, coefficient)
-                        points.update({dim:num})
-                vertices_points.append(points)
-                print(points)
-                    
+                            num = -Fraction(constant, coefficient)
+                            points[dim]= float(num)
+                vertices_points.append(points.copy())
             else:
                 points = []
                 string = islhelper.isl_multi_aff_to_str(expr)

diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py
index 63ecb64..db99753 100644 (file)
--- a/pypol/polyhedra.py
+++ b/pypol/polyhedra.py
@@ -1,10 +1,11 @@
+
 import functools
 import numbers
 
 from . import islhelper
 
 from .islhelper import mainctx, libisl
-from .linexprs import Expression, Rational
+from .linexprs import Expression, Symbol, Rational
 from .domains import Domain
 
 
@@ -194,6 +195,45 @@ class Polyhedron(Domain):
         for inequality in self.inequalities:
             constraints.append(sympy.Ge(inequality.tosympy(), 0))
         return sympy.And(*constraints)
+    
+    def plot(self):
+        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)
+            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
 
 
 def _polymorphic(func):