Unitary tests for Polyhedron, very incomplete
[linpy.git] / tests / test_linear.py
index 4636275..f02c4f4 100644 (file)
@@ -1,4 +1,4 @@
-
+import functools
 import unittest
 
 from fractions import Fraction
@@ -6,165 +6,223 @@ 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):
-        self.x = symbol('x')
-        self.y = symbol('y')
-        self.z = symbol('z')
-        self.zero = constant(0)
-        self.pi = constant(Fraction(22, 7))
-        self.e = self.x - 2*self.y + 3
-
-    def test_new(self):
-        pass
+        self.x = Expression({'x': 1})
+        self.y = Expression({'y': 1})
+        self.z = Expression({'z': 1})
+        self.zero = Expression(constant=0)
+        self.one = Expression(constant=1)
+        self.pi = Expression(constant=Fraction(22, 7))
+        self.expr = self.x - 2*self.y + 3
+
+    def test_new_subclass(self):
+        self.assertIsInstance(self.x, Symbol)
+        self.assertIsInstance(self.pi, Constant)
+        self.assertNotIsInstance(self.x + self.pi, Symbol)
+        self.assertNotIsInstance(self.x + self.pi, Constant)
+        xx = Expression({'x': 2})
+        self.assertNotIsInstance(xx, Symbol)
+
+    def test_new_types(self):
+        with self.assertRaises(TypeError):
+            Expression('x + y', 2)
+        self.assertEqual(Expression({'x': 2}), Expression({self.x: 2}))
+        with self.assertRaises(TypeError):
+            Expression({0: 2})
+        with self.assertRaises(TypeError):
+            Expression({'x': '2'})
+        self.assertEqual(Expression(constant=1), Expression(constant=self.one))
+        with self.assertRaises(TypeError):
+            Expression(constant='1')
 
     def test_symbols(self):
-        self.assertCountEqual(self.x.symbols(), ['x'])
-        self.assertCountEqual(self.pi.symbols(), [])
-        self.assertCountEqual(self.e.symbols(), ['x', 'y'])
+        self.assertCountEqual(self.x.symbols, ['x'])
+        self.assertCountEqual(self.pi.symbols, [])
+        self.assertCountEqual(self.expr.symbols, ['x', 'y'])
 
     def test_dimension(self):
         self.assertEqual(self.x.dimension, 1)
         self.assertEqual(self.pi.dimension, 0)
-        self.assertEqual(self.e.dimension, 2)
+        self.assertEqual(self.expr.dimension, 2)
 
     def test_coefficient(self):
-        self.assertEqual(self.e.coefficient('x'), 1)
-        self.assertEqual(self.e.coefficient('y'), -2)
-        self.assertEqual(self.e.coefficient(self.y), -2)
-        self.assertEqual(self.e.coefficient('z'), 0)
+        self.assertEqual(self.expr.coefficient('x'), 1)
+        self.assertEqual(self.expr.coefficient('y'), -2)
+        self.assertEqual(self.expr.coefficient(self.y), -2)
+        self.assertEqual(self.expr.coefficient('z'), 0)
         with self.assertRaises(TypeError):
-            self.e.coefficient(0)
+            self.expr.coefficient(0)
         with self.assertRaises(TypeError):
-            self.e.coefficient(self.e)
+            self.expr.coefficient(self.expr)
 
     def test_getitem(self):
-        self.assertEqual(self.e['x'], 1)
-        self.assertEqual(self.e['y'], -2)
-        self.assertEqual(self.e[self.y], -2)
-        self.assertEqual(self.e['z'], 0)
+        self.assertEqual(self.expr['x'], 1)
+        self.assertEqual(self.expr['y'], -2)
+        self.assertEqual(self.expr[self.y], -2)
+        self.assertEqual(self.expr['z'], 0)
         with self.assertRaises(TypeError):
-            self.e[0]
+            self.expr[0]
         with self.assertRaises(TypeError):
-            self.e[self.e]
+            self.expr[self.expr]
 
     def test_coefficients(self):
-        self.assertCountEqual(self.e.coefficients(), [('x', 1), ('y', -2)])
+        self.assertCountEqual(self.expr.coefficients(), [('x', 1), ('y', -2)])
 
     def test_constant(self):
         self.assertEqual(self.x.constant, 0)
         self.assertEqual(self.pi.constant, Fraction(22, 7))
-        self.assertEqual(self.e.constant, 3)
+        self.assertEqual(self.expr.constant, 3)
 
     def test_isconstant(self):
         self.assertFalse(self.x.isconstant())
         self.assertTrue(self.pi.isconstant())
-        self.assertFalse(self.e.isconstant())
+        self.assertFalse(self.expr.isconstant())
 
     def test_values(self):
-        self.assertCountEqual(self.e.values(), [1, -2, 3])
-
-    def test_symbol(self):
-        self.assertEqual(self.x.symbol(), 'x')
-        with self.assertRaises(ValueError):
-            self.pi.symbol()
-        with self.assertRaises(ValueError):
-            self.e.symbol()
+        self.assertCountEqual(self.expr.values(), [1, -2, 3])
 
     def test_issymbol(self):
         self.assertTrue(self.x.issymbol())
         self.assertFalse(self.pi.issymbol())
-        self.assertFalse(self.e.issymbol())
+        self.assertFalse(self.expr.issymbol())
 
     def test_bool(self):
         self.assertTrue(self.x)
         self.assertFalse(self.zero)
         self.assertTrue(self.pi)
-        self.assertTrue(self.e)
+        self.assertTrue(self.expr)
 
     def test_pos(self):
-        self.assertEqual(+self.e, self.e)
+        self.assertEqual(+self.expr, self.expr)
 
     def test_neg(self):
-        self.assertEqual(-self.e, -self.x + 2*self.y - 3)
+        self.assertEqual(-self.expr, -self.x + 2*self.y - 3)
 
     def test_add(self):
         self.assertEqual(self.x + Fraction(22, 7), self.x + self.pi)
         self.assertEqual(Fraction(22, 7) + self.x, self.x + self.pi)
         self.assertEqual(self.x + self.x, 2 * self.x)
-        self.assertEqual(self.e + 2*self.y, self.x + 3)
+        self.assertEqual(self.expr + 2*self.y, self.x + 3)
 
     def test_sub(self):
         self.assertEqual(self.x - self.x, 0)
-        self.assertEqual(self.e - 3, self.x - 2*self.y)
+        self.assertEqual(self.expr - 3, self.x - 2*self.y)
+        self.assertEqual(0 - self.x, -self.x)
 
     def test_mul(self):
         self.assertEqual(self.pi * 7, 22)
-        self.assertEqual(self.e * 0, 0)
-        self.assertEqual(self.e * 2, 2*self.x - 4*self.y + 6)
+        self.assertEqual(self.expr * 0, 0)
+        self.assertEqual(0 * self.expr, 0)
+        self.assertEqual(self.expr * 2, 2*self.x - 4*self.y + 6)
 
     def test_div(self):
         with self.assertRaises(ZeroDivisionError):
-            self.e / 0
-        self.assertEqual(self.e / 2, self.x / 2 - self.y + Fraction(3, 2))
+            self.expr / 0
+        self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 
     def test_str(self):
         self.assertEqual(str(Expression()), '0')
         self.assertEqual(str(self.x), 'x')
         self.assertEqual(str(-self.x), '-x')
         self.assertEqual(str(self.pi), '22/7')
-        self.assertEqual(str(self.e), 'x - 2*y + 3')
+        self.assertEqual(str(self.expr), 'x - 2*y + 3')
 
     def test_repr(self):
-        self.assertEqual(repr(self.e), "Expression({'x': 1, 'y': -2}, 3)")
+        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(Expression.fromstring('22/7'), self.pi)
-        self.assertEqual(Expression.fromstring('x - 2y + 3'), self.e)
-        self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.e)
-        self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.e)
+        self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
+        self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
+        self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
 
     def test_eq(self):
-        self.assertEqual(self.e, self.e)
+        self.assertEqual(self.expr, self.expr)
         self.assertNotEqual(self.x, self.y)
         self.assertEqual(self.zero, 0)
 
-    def test_canonify(self):
-        self.assertEqual((self.x + self.y/2 + self.z/3)._canonify(),
+    def test__toint(self):
+        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 TestHelpers(unittest.TestCase):
+class TestConstant(unittest.TestCase):
 
     def setUp(self):
-        self.x = symbol('x')
-        self.y = symbol('y')
+        self.zero = Constant(0)
+        self.one = Constant(1)
+        self.pi = Constant(Fraction(22, 7))
 
-    def test_constant(self):
-        self.assertEqual(constant(3), 3)
-        self.assertEqual(constant('3'), 3)
-        self.assertEqual(constant(Fraction(3, 4)), Fraction(3, 4))
-        self.assertEqual(constant('3/4'), Fraction(3, 4))
-        with self.assertRaises(ValueError):
-            constant('a')
+    @_with_sympy
+    def test_fromsympy(self):
+        self.assertEqual(Constant.fromsympy(sympy.Rational(22, 7)), self.pi)
         with self.assertRaises(TypeError):
-            constant([])
+            Constant.fromsympy(sympy.Symbol('x'))
 
-    def test_symbol(self):
-        self.assertEqual(symbol('x'), self.x)
-        self.assertNotEqual(symbol('y'), self.x)
-        with self.assertRaises(TypeError):
-            symbol(0)
+
+class TestSymbol(unittest.TestCase):
+
+    def setUp(self):
+        self.x = Symbol('x')
+        self.y = Symbol('y')
+
+    def test_name(self):
+        self.assertEqual(self.x.name, 'x')
 
     def test_symbols(self):
         self.assertListEqual(list(symbols('x y')), [self.x, self.y])
         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):
 
@@ -173,5 +231,39 @@ 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))