pypol/tests/test_polyhedra.py

   1 import functools
   2 import unittest
   3
   4 from ..linexprs import symbols
   5 from ..polyhedra import *
   6
   7
   8 try:
   9     import sympy
  10     def _requires_sympy(func):
  11         @functools.wraps(func)
  12         def wrapper(self):
  13             return func(self)
  14         return wrapper
  15 except ImportError:
  16     def _requires_sympy(func):
  17         @functools.wraps(func)
  18         def wrapper(self):
  19             raise unittest.SkipTest('SymPy is not available')
  20         return wrapper
  21
  22
  23 class TestPolyhedron(unittest.TestCase):
  24
  25     def setUp(self):
  26         x, y = symbols('x y')
  27         self.square = Polyhedron(inequalities=[x, 1 - x, y, 1 - y])
  28
  29     def test_symbols(self):
  30         self.assertCountEqual(self.square.symbols, ['x', 'y'])
  31
  32     def test_dimension(self):
  33         self.assertEqual(self.square.dimension, 2)
  34
  35     def test_str(self):
  36         self.assertEqual(str(self.square),
  37             'And(Ge(x, 0), Ge(-x + 1, 0), Ge(y, 0), Ge(-y + 1, 0))')
  38
  39     def test_repr(self):
  40         self.assertEqual(repr(self.square),
  41             "And(Ge(x, 0), Ge(-x + 1, 0), Ge(y, 0), Ge(-y + 1, 0))")
  42
  43     def test_fromstring(self):
  44         self.assertEqual(Polyhedron.fromstring('{x >= 0, -x + 1 >= 0, '
  45             'y >= 0, -y + 1 >= 0}'), 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         sp_x, sp_y = sympy.symbols('x y')
  56         self.assertEqual(Polyhedron.fromsympy((sp_x >= 0) & (sp_x <= 1) &
  57             (sp_y >= 0) & (sp_y <= 1)), self.square)
  58
  59     @_requires_sympy
  60     def test_tosympy(self):
  61         sp_x, sp_y = sympy.symbols('x y')
  62         self.assertEqual(self.square.tosympy(),
  63             sympy.And(-sp_x + 1 >= 0, -sp_y + 1 >= 0, sp_x >= 0, sp_y >= 0))
  64
  65
  66 class TestEmpty:
  67
  68     def test_repr(self):
  69         self.assertEqual(repr(Empty), 'Empty')
  70
  71     def test_isempty(self):
  72         self.assertTrue(Empty.isempty())
  73
  74     def test_isuniverse(self):
  75         self.assertFalse(Empty.isuniverse())
  76
  77
  78 class TestUniverse:
  79
  80     def test_repr(self):
  81         self.assertEqual(repr(Universe), 'Universe')
  82
  83     def test_isempty(self):
  84         self.assertTrue(Universe.isempty())
  85
  86     def test_isuniverse(self):
  87         self.assertTrue(Universe.isuniverse())