From: Vivien Maisonneuve Date: Sat, 12 Jul 2014 08:18:43 +0000 (+0200) Subject: Fix methods Domain._sort_polygon_2d(), Domain._sort_polygon_3d() X-Git-Tag: 1.0~116 X-Git-Url: https://scm.cri.mines-paristech.fr/git/linpy.git/commitdiff_plain/8332ae24f41a1f2bbba78597cc9e412ef9935ae8?ds=inline;hp=2c669de47805cf0b8bd1c8bcf3958f52b1902926 Fix methods Domain._sort_polygon_2d(), Domain._sort_polygon_3d() --- diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py index 37f16e0..69ed2b2 100644 --- a/pypol/polyhedra.py +++ b/pypol/polyhedra.py @@ -5,7 +5,7 @@ import numbers from . import islhelper from .islhelper import mainctx, libisl -from .geometry import GeometricObject, Point +from .geometry import GeometricObject, Point, Vector from .linexprs import Expression, Symbol, Rational from .domains import Domain @@ -206,16 +206,26 @@ 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 = sum((Vector(point) for point in points)) / len(points) - o = Point(o.coordinates()) + o = cls._polygon_inner_point(points) angles = {} for m in points: om = Vector(o, m) - dx, dy = (coordinate for symbol, coordinates in om.coordinates()) + dx, dy = (coordinate for symbol, coordinate in om.coordinates()) angle = math.atan2(dy, dx) angles[m] = angle return sorted(points, key=angles.get) @@ -224,13 +234,18 @@ class Polyhedron(Domain): def _sort_polygon_3d(cls, points): if len(points) <= 3: return points - o = sum((Vector(point) for point in points)) / len(points) - o = Point(o.coordinates()) - a, b = points[:2] + o = cls._polygon_inner_point(points) + a = points[0] oa = Vector(o, a) - ob = Vector(o, b) norm_oa = oa.norm() - u = (oa.cross(ob)).asunit() + 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)