+import functools
import unittest
from fractions import Fraction
from pypol.linear import *
+try:
+ import sympy
+ def _with_sympy(func):
+ @functools.wraps(func)
+ def wrapper(self):
+ return func(self)
+ return wrapper
+except ImportError:
+ def _with_sympy(func):
+ @functools.wraps(func)
+ def wrapper(self):
+ raise unittest.SkipTest('SymPy is not available')
+ return wrapper
+
+
class TestExpression(unittest.TestCase):
def setUp(self):
def test_repr(self):
self.assertEqual(repr(self.x), "Symbol('x')")
self.assertEqual(repr(self.one), 'Constant(1)')
+ self.assertEqual(repr(self.pi), 'Constant(22, 7)')
self.assertEqual(repr(self.expr), "Expression({'x': 1, 'y': -2}, 3)")
- @unittest.expectedFailure
def test_fromstring(self):
self.assertEqual(Expression.fromstring('x'), self.x)
self.assertEqual(Expression.fromstring('-x'), -self.x)
self.assertEqual((self.x + self.y/2 + self.z/3)._toint(),
6*self.x + 3*self.y + 2*self.z)
+ @_with_sympy
+ def test_fromsympy(self):
+ sp_x, sp_y = sympy.symbols('x y')
+ self.assertEqual(Expression.fromsympy(sp_x), self.x)
+ self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
+ self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
+ with self.assertRaises(ValueError):
+ Expression.fromsympy(sp_x*sp_y)
+
+ @_with_sympy
+ def test_tosympy(self):
+ sp_x, sp_y = sympy.symbols('x y')
+ self.assertEqual(self.x.tosympy(), sp_x)
+ self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
+ self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
+
class TestConstant(unittest.TestCase):
- pass
+ def setUp(self):
+ self.zero = Constant(0)
+ self.one = Constant(1)
+ self.pi = Constant(Fraction(22, 7))
+
+ @_with_sympy
+ def test_fromsympy(self):
+ self.assertEqual(Constant.fromsympy(sympy.Rational(22, 7)), self.pi)
+ with self.assertRaises(TypeError):
+ Constant.fromsympy(sympy.Symbol('x'))
class TestSymbol(unittest.TestCase):
self.assertListEqual(list(symbols('x,y')), [self.x, self.y])
self.assertListEqual(list(symbols(['x', 'y'])), [self.x, self.y])
+ @_with_sympy
+ def test_fromsympy(self):
+ sp_x = sympy.Symbol('x')
+ self.assertEqual(Symbol.fromsympy(sp_x), self.x)
+ with self.assertRaises(TypeError):
+ Symbol.fromsympy(sympy.Rational(22, 7))
+ with self.assertRaises(TypeError):
+ Symbol.fromsympy(2 * sp_x)
+ with self.assertRaises(TypeError):
+ Symbol.fromsympy(sp_x*sp_x)
+
class TestOperators(unittest.TestCase):
class TestPolyhedron(unittest.TestCase):
- pass
+ def setUp(self):
+ x, y = symbols('x y')
+ self.square = Polyhedron(inequalities=[x, 1 - x, y, 1 - y])
+
+ def test_symbols(self):
+ self.assertCountEqual(self.square.symbols, ['x', 'y'])
+
+ def test_dimension(self):
+ self.assertEqual(self.square.dimension, 2)
+
+ def test_tostring(self):
+ self.assertEqual(str(self.square),
+ '{x >= 0, -x + 1 >= 0, y >= 0, -y + 1 >= 0}')
+
+ def test_fromstring(self):
+ self.assertEqual(Polyhedron.fromstring('{x >= 0, -x + 1 >= 0, '
+ 'y >= 0, -y + 1 >= 0}'), self.square)
+
+ def test_isempty(self):
+ self.assertFalse(self.square.isempty())
+
+ def test_isuniverse(self):
+ self.assertFalse(self.square.isuniverse())
+
+ @unittest.expectedFailure
+ @_with_sympy
+ def test_fromsympy(self):
+ sp_x, sp_y = sympy.symbols('x y')
+ self.assertEqual(Polyhedron.fromsympy((sp_x >= 0) & (sp_x <= 1) &
+ (sp_y >= 0) & (sp_y <= 1)), self.square)
+
+ @_with_sympy
+ def test_tosympy(self):
+ sp_x, sp_y = sympy.symbols('x y')
+ self.assertEqual(self.square.tosympy(),
+ sympy.And(-sp_x + 1 >= 0, -sp_y + 1 >= 0, sp_x >= 0, sp_y >= 0))