Add plot method

[linpy.git] / pypol / domains.py

diff --git a/pypol/domains.py b/pypol/domains.py
index 6088e32..375be85 100644 (file)
--- a/pypol/domains.py
+++ b/pypol/domains.py
@@ -2,8 +2,9 @@ import ast
 import functools
 import re
 
-from . import islhelper
+from fractions import Fraction
 
+from . import islhelper
 from .islhelper import mainctx, libisl, isl_set_basic_sets
 from .linexprs import Expression, Symbol
 
@@ -168,17 +169,17 @@ class Domain:
         return Domain._fromislset(islset, dims)
 
     def sample(self):
-        from .polyhedra import Polyhedron
         islset = self._toislset(self.polyhedra, self.symbols)
         islpoint = libisl.isl_set_sample_point(islset)
+        if bool(libisl.isl_point_is_void(islpoint)):
+            libisl.isl_point_free(islpoint)
+            raise ValueError('domain must be non-empty')
         point = {}
         for index, symbol in enumerate(self.symbols):
             coordinate = libisl.isl_point_get_coordinate_val(islpoint,
                 libisl.isl_dim_set, index)
             coordinate = islhelper.isl_val_to_int(coordinate)
             point[symbol] = coordinate
-        if bool(libisl.isl_point_is_void(islpoint)):
-            point = None
         libisl.isl_point_free(islpoint)
         return point
 
@@ -256,21 +257,48 @@ class Domain:
         libisl.isl_set_free(islset)
         return value
 
+    _RE_COORDINATE = re.compile(r'\((?P<num>\-?\d+)\)(/(?P<den>\d+))?')
+
     def vertices(self):
+        #returning list of verticies
+        from .polyhedra import Polyhedron
         islbset = self._toislbasicset(self.equalities, self.inequalities, self.symbols)
         vertices = libisl.isl_basic_set_compute_vertices(islbset);
         vertices = islhelper.isl_vertices_vertices(vertices)
+        points = {}
+        num = 0
+        vertices_points = []
         for vertex in vertices:
-            expr = libisl.isl_vertex_get_expr(vertex);
             if islhelper.isl_version < '0.13':
-                string = islhelper.isl_set_to_str(expr)
+                expr = libisl.isl_vertex_get_expr(vertex)
+                constraints = islhelper.isl_basic_set_constraints(expr) #get bset constraints
+                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[dim]= float(num)
+                vertices_points.append(points.copy())
             else:
+                points = []
                 string = islhelper.isl_multi_aff_to_str(expr)
-            print(string)
-
+                matches = self._RE_COORDINATE.finditer(string)
+                point = {}
+                for symbol, match in zip(self.symbols, matches):
+                    numerator = int(match.group('num'))
+                    denominator = match.group('den')
+                    denominator = 1 if denominator is None else int(denominator)
+                    coordinate = Fraction(numerator, denominator)
+                    point[symbol] = coordinate
+                points.append(point)
+        return vertices_points
+    
     def points(self):
         if not self.isbounded():
-            raise ValueError('domain must be unbounded')
+            raise ValueError('domain must be bounded')
         from .polyhedra import Universe, Eq
         islset = self._toislset(self.polyhedra, self.symbols)
         islpoints = islhelper.isl_set_points(islset)
@@ -285,6 +313,11 @@ class Domain:
             points.append(point)
         return points
 
+    def subs(self, symbol, expression=None):
+        polyhedra = [polyhedron.subs(symbol, expression)
+            for polyhedron in self.polyhedra]
+        return Domain(*polyhedra)
+
     @classmethod
     def _fromislset(cls, islset, symbols):
         from .polyhedra import Polyhedron
@@ -307,6 +340,7 @@ class Domain:
             self._dimension = len(self._symbols)
             return self
 
+    @classmethod
     def _toislset(cls, polyhedra, symbols):
         polyhedron = polyhedra[0]
         islbset = polyhedron._toislbasicset(polyhedron.equalities,