linpy/tests/test_polyhedra.py

   1 # Copyright 2014 MINES ParisTech
   2 #
   3 # This file is part of LinPy.
   4 #
   5 # LinPy is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # LinPy is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with LinPy.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import unittest
  19
  20 from ..linexprs import symbols
  21 from ..polyhedra import Empty, Polyhedron, Universe
  22 from .libhelper import requires_sympy
  23
  24
  25 class TestPolyhedron(unittest.TestCase):
  26
  27     def setUp(self):
  28         x, y = symbols('x y')
  29         self.square = Polyhedron(inequalities=[x, 1 - x, y, 1 - y])
  30
  31     def test_symbols(self):
  32         self.assertTupleEqual(self.square.symbols, symbols('x y'))
  33
  34     def test_dimension(self):
  35         self.assertEqual(self.square.dimension, 2)
  36
  37     def test_repr(self):
  38         self.assertEqual(repr(self.square),
  39                          'And(0 <= x, x <= 1, 0 <= y, y <= 1)')
  40
  41     def test_fromstring(self):
  42         self.assertEqual(
  43             Polyhedron.fromstring(
  44                 '{x >= 0, -x + 1 >= 0, y >= 0, -y + 1 >= 0}'),
  45             self.square)
  46
  47     def test_isempty(self):
  48         self.assertFalse(self.square.isempty())
  49
  50     def test_isuniverse(self):
  51         self.assertFalse(self.square.isuniverse())
  52
  53     @requires_sympy
  54     def test_fromsympy(self):
  55         import sympy
  56         sp_x, sp_y = sympy.symbols('x y')
  57         self.assertEqual(
  58             Polyhedron.fromsympy(
  59                 (sp_x >= 0) & (sp_x <= 1) & (sp_y >= 0) & (sp_y <= 1)),
  60             self.square)
  61
  62     @requires_sympy
  63     def test_tosympy(self):
  64         import sympy
  65         sp_x, sp_y = sympy.symbols('x y')
  66         self.assertEqual(
  67             self.square.tosympy(),
  68             sympy.And(-sp_x + 1 >= 0, -sp_y + 1 >= 0, sp_x >= 0, sp_y >= 0))
  69
  70
  71 class TestEmpty:
  72
  73     def test_repr(self):
  74         self.assertEqual(repr(Empty), 'Empty')
  75
  76     def test_isempty(self):
  77         self.assertTrue(Empty.isempty())
  78
  79     def test_isuniverse(self):
  80         self.assertFalse(Empty.isuniverse())
  81
  82
  83 class TestUniverse:
  84
  85     def test_repr(self):
  86         self.assertEqual(repr(Universe), 'Universe')
  87
  88     def test_isempty(self):
  89         self.assertTrue(Universe.isempty())
  90
  91     def test_isuniverse(self):
  92         self.assertTrue(Universe.isuniverse())