X-Git-Url: https://svn.cri.ensmp.fr/git/linpy.git/blobdiff_plain/2a1055d4f4754fa33c53d3f155cc050e4911a2a3..77d9e641db24dc1edb6d0e2b91b58d395761616f:/pypol/polyhedra.py diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py index a5048d1..f8d413e 100644 --- a/pypol/polyhedra.py +++ b/pypol/polyhedra.py @@ -5,8 +5,8 @@ import numbers from . import islhelper from .islhelper import mainctx, libisl -from .geometry import GeometricObject, Point, Vector -from .linexprs import Expression, Symbol, Rational +from .geometry import GeometricObject, Point +from .linexprs import Expression, Rational from .domains import Domain @@ -114,6 +114,10 @@ class Polyhedron(Domain): @classmethod def _fromislbasicset(cls, islbset, symbols): + if libisl.isl_basic_set_is_empty(islbset): + return Empty + if libisl.isl_basic_set_is_universe(islbset): + return Universe islconstraints = islhelper.isl_basic_set_constraints(islbset) equalities = [] inequalities = [] @@ -184,33 +188,23 @@ class Polyhedron(Domain): return domain def __repr__(self): - if self.isempty(): - return 'Empty' - elif self.isuniverse(): - return 'Universe' + strings = [] + for equality in self.equalities: + strings.append('Eq({}, 0)'.format(equality)) + for inequality in self.inequalities: + strings.append('Ge({}, 0)'.format(inequality)) + if len(strings) == 1: + return strings[0] else: - strings = [] - for equality in self.equalities: - strings.append('Eq({}, 0)'.format(equality)) - for inequality in self.inequalities: - strings.append('Ge({}, 0)'.format(inequality)) - if len(strings) == 1: - return strings[0] - else: - return 'And({})'.format(', '.join(strings)) + return 'And({})'.format(', '.join(strings)) def _repr_latex_(self): - if self.isempty(): - return '$\\emptyset$' - elif self.isuniverse(): - return '$\\Omega$' - else: - strings = [] - for equality in self.equalities: - strings.append('{} = 0'.format(equality._repr_latex_().strip('$'))) - for inequality in self.inequalities: - strings.append('{} \\ge 0'.format(inequality._repr_latex_().strip('$'))) - return '${}$'.format(' \\wedge '.join(strings)) + strings = [] + for equality in self.equalities: + strings.append('{} = 0'.format(equality._repr_latex_().strip('$'))) + for inequality in self.inequalities: + strings.append('{} \\ge 0'.format(inequality._repr_latex_().strip('$'))) + return '$${}$$'.format(' \\wedge '.join(strings)) @classmethod def fromsympy(cls, expr): @@ -228,127 +222,49 @@ class Polyhedron(Domain): constraints.append(sympy.Ge(inequality.tosympy(), 0)) return sympy.And(*constraints) - @classmethod - def _polygon_inner_point(cls, points): - symbols = points[0].symbols - coordinates = {symbol: 0 for symbol in symbols} - for point in points: - for symbol, coordinate in point.coordinates(): - coordinates[symbol] += coordinate - for symbol in symbols: - coordinates[symbol] /= len(points) - return Point(coordinates) - @classmethod - def _sort_polygon_2d(cls, points): - if len(points) <= 3: - return points - o = cls._polygon_inner_point(points) - angles = {} - for m in points: - om = Vector(o, m) - dx, dy = (coordinate for symbol, coordinate in om.coordinates()) - angle = math.atan2(dy, dx) - angles[m] = angle - return sorted(points, key=angles.get) +class EmptyType(Polyhedron): + + __slots__ = Polyhedron.__slots__ + + def __new__(cls): + self = object().__new__(cls) + self._equalities = (Rational(1),) + self._inequalities = () + self._constraints = self._equalities + self._symbols = () + self._dimension = 0 + return self + + def __repr__(self): + return 'Empty' + + def _repr_latex_(self): + return '$$\\emptyset$$' + +Empty = EmptyType() - @classmethod - def _sort_polygon_3d(cls, points): - if len(points) <= 3: - return points - o = cls._polygon_inner_point(points) - a = points[0] - oa = Vector(o, a) - norm_oa = oa.norm() - for b in points[1:]: - ob = Vector(o, b) - u = oa.cross(ob) - if not u.isnull(): - u = u.asunit() - break - else: - raise ValueError('degenerate polygon') - angles = {a: 0.} - for m in points[1:]: - om = Vector(o, m) - normprod = norm_oa * om.norm() - cosinus = max(oa.dot(om) / normprod, -1.) - sinus = u.dot(oa.cross(om)) / normprod - angle = math.acos(cosinus) - angle = math.copysign(angle, sinus) - angles[m] = angle - return sorted(points, key=angles.get) - - def faces(self): - vertices = self.vertices() - faces = [] - for constraint in self.constraints: - face = [] - for vertex in vertices: - if constraint.subs(vertex.coordinates()) == 0: - face.append(vertex) - faces.append(face) - return faces - - def _plot_2d(self, plot=None, **kwargs): - from matplotlib import pylab - import matplotlib.pyplot as plt - from matplotlib.axes import Axes - 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() - plot = fig.add_subplot(1, 1, 1) - xs, ys = zip(*xys) - plot.set_xlim(float(min(xs)), float(max(xs))) - plot.set_ylim(float(min(ys)), float(max(ys))) - 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) - xmin, xmax = float('inf'), float('-inf') - ymin, ymax = float('inf'), float('-inf') - zmin, zmax = float('inf'), float('-inf') - else: - axes = plot - 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] - if plot is None: - 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) - if plot is None: - 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') + +class UniverseType(Polyhedron): + + __slots__ = Polyhedron.__slots__ + + def __new__(cls): + self = object().__new__(cls) + self._equalities = () + self._inequalities = () + self._constraints = () + self._symbols = () + self._dimension = () + return self + + def __repr__(self): + return 'Universe' + + def _repr_latex_(self): + return '$$\\Omega$$' + +Universe = UniverseType() def _polymorphic(func): @@ -410,8 +326,3 @@ def Ge(left, right): Return true if the first set is greater than or equal the second set. """ return Polyhedron([], [left - right]) - - -Empty = Eq(1, 0) - -Universe = Polyhedron([])