X-Git-Url: https://scm.cri.ensmp.fr/git/linpy.git/blobdiff_plain/d2ec7dd24a7eeab018d12e3ae27d2d1c7226a7f3..ce985e833f88aed8957c73434198e6bac6bd234e:/pypol/polyhedra.py diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py index f93f31e..db99753 100644 --- 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 @@ -37,7 +38,7 @@ class Polyhedron(Domain): elif isinstance(equalities, Domain): if inequalities is not None: raise TypeError('too many arguments') - return equalities.polyhedral_hull() + return equalities.aspolyhedron() if equalities is None: equalities = [] else: @@ -82,9 +83,16 @@ class Polyhedron(Domain): libisl.isl_basic_set_free(islbset) return universe - def polyhedral_hull(self): + def aspolyhedron(self): return self + def subs(self, symbol, expression=None): + equalities = [equality.subs(symbol, expression) + for equality in self.equalities] + inequalities = [inequality.subs(symbol, expression) + for inequality in self.inequalities] + return Polyhedron(equalities, inequalities) + @classmethod def _fromislbasicset(cls, islbset, symbols): islconstraints = islhelper.isl_basic_set_constraints(islbset) @@ -187,6 +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):