pypol/tests/test_linexprs.py

   1 import functools
   2 import unittest
   3
   4 from fractions import Fraction
   5
   6 from ..linexprs import *
   7
   8
   9 try:
  10     import sympy
  11     def _requires_sympy(func):
  12         @functools.wraps(func)
  13         def wrapper(self):
  14             return func(self)
  15         return wrapper
  16 except ImportError:
  17     def _requires_sympy(func):
  18         @functools.wraps(func)
  19         def wrapper(self):
  20             raise unittest.SkipTest('SymPy is not available')
  21         return wrapper
  22
  23
  24 class TestExpression(unittest.TestCase):
  25
  26     def setUp(self):
  27         self.x = Expression({'x': 1})
  28         self.y = Expression({'y': 1})
  29         self.z = Expression({'z': 1})
  30         self.zero = Expression(constant=0)
  31         self.one = Expression(constant=1)
  32         self.pi = Expression(constant=Fraction(22, 7))
  33         self.expr = self.x - 2*self.y + 3
  34
  35     def test_new(self):
  36         self.assertIsInstance(self.x, Symbol)
  37         self.assertIsInstance(self.pi, Constant)
  38         self.assertNotIsInstance(self.x + self.pi, Symbol)
  39         self.assertNotIsInstance(self.x + self.pi, Constant)
  40         xx = Expression({'x': 2})
  41         self.assertNotIsInstance(xx, Symbol)
  42         with self.assertRaises(TypeError):
  43             Expression('x + y', 2)
  44         self.assertEqual(Expression({'x': 2}), Expression({self.x: 2}))
  45         with self.assertRaises(TypeError):
  46             Expression({0: 2})
  47         with self.assertRaises(TypeError):
  48             Expression({'x': '2'})
  49         self.assertEqual(Expression(constant=1), Expression(constant=self.one))
  50         self.assertEqual(Expression(constant='1'), Expression(constant=self.one))
  51         with self.assertRaises(ValueError):
  52             Expression(constant='a')
  53
  54     def test_coefficient(self):
  55         self.assertEqual(self.expr.coefficient('x'), 1)
  56         self.assertEqual(self.expr.coefficient('y'), -2)
  57         self.assertEqual(self.expr.coefficient(self.y), -2)
  58         self.assertEqual(self.expr.coefficient('z'), 0)
  59         with self.assertRaises(TypeError):
  60             self.expr.coefficient(0)
  61         with self.assertRaises(TypeError):
  62             self.expr.coefficient(self.expr)
  63
  64     def test_getitem(self):
  65         self.assertEqual(self.expr['x'], 1)
  66         self.assertEqual(self.expr['y'], -2)
  67         self.assertEqual(self.expr[self.y], -2)
  68         self.assertEqual(self.expr['z'], 0)
  69         with self.assertRaises(TypeError):
  70             self.expr[0]
  71         with self.assertRaises(TypeError):
  72             self.expr[self.expr]
  73
  74     def test_coefficients(self):
  75         self.assertCountEqual(self.expr.coefficients(), [('x', 1), ('y', -2)])
  76
  77     def test_constant(self):
  78         self.assertEqual(self.x.constant, 0)
  79         self.assertEqual(self.pi.constant, Fraction(22, 7))
  80         self.assertEqual(self.expr.constant, 3)
  81
  82     def test_symbols(self):
  83         self.assertCountEqual(self.x.symbols, ['x'])
  84         self.assertCountEqual(self.pi.symbols, [])
  85         self.assertCountEqual(self.expr.symbols, ['x', 'y'])
  86
  87     def test_dimension(self):
  88         self.assertEqual(self.x.dimension, 1)
  89         self.assertEqual(self.pi.dimension, 0)
  90         self.assertEqual(self.expr.dimension, 2)
  91
  92     def test_isconstant(self):
  93         self.assertFalse(self.x.isconstant())
  94         self.assertTrue(self.pi.isconstant())
  95         self.assertFalse(self.expr.isconstant())
  96
  97     def test_issymbol(self):
  98         self.assertTrue(self.x.issymbol())
  99         self.assertFalse(self.pi.issymbol())
 100         self.assertFalse(self.expr.issymbol())
 101
 102     def test_values(self):
 103         self.assertCountEqual(self.expr.values(), [1, -2, 3])
 104
 105     def test_bool(self):
 106         self.assertTrue(self.x)
 107         self.assertFalse(self.zero)
 108         self.assertTrue(self.pi)
 109         self.assertTrue(self.expr)
 110
 111     def test_pos(self):
 112         self.assertEqual(+self.expr, self.expr)
 113
 114     def test_neg(self):
 115         self.assertEqual(-self.expr, -self.x + 2*self.y - 3)
 116
 117     def test_add(self):
 118         self.assertEqual(self.x + Fraction(22, 7), self.x + self.pi)
 119         self.assertEqual(Fraction(22, 7) + self.x, self.x + self.pi)
 120         self.assertEqual(self.x + self.x, 2 * self.x)
 121         self.assertEqual(self.expr + 2*self.y, self.x + 3)
 122
 123     def test_sub(self):
 124         self.assertEqual(self.x - self.x, 0)
 125         self.assertEqual(self.expr - 3, self.x - 2*self.y)
 126         self.assertEqual(0 - self.x, -self.x)
 127
 128     def test_mul(self):
 129         self.assertEqual(self.pi * 7, 22)
 130         self.assertEqual(self.expr * 0, 0)
 131         self.assertEqual(0 * self.expr, 0)
 132         self.assertEqual(self.expr * 2, 2*self.x - 4*self.y + 6)
 133
 134     def test_truediv(self):
 135         with self.assertRaises(ZeroDivisionError):
 136             self.expr / 0
 137         self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 138
 139     def test_eq(self):
 140         self.assertEqual(self.expr, self.expr)
 141         self.assertNotEqual(self.x, self.y)
 142         self.assertEqual(self.zero, 0)
 143
 144     def test__toint(self):
 145         self.assertEqual((self.x + self.y/2 + self.z/3)._toint(),
 146                 6*self.x + 3*self.y + 2*self.z)
 147
 148     def test_subs(self):
 149         self.assertEqual(self.x.subs('x', 3), 3)
 150         self.assertEqual(self.x.subs('x', self.x), self.x)
 151         self.assertEqual(self.x.subs('x', self.y), self.y)
 152         self.assertEqual(self.x.subs('x', self.x + self.y), self.x + self.y)
 153         self.assertEqual(self.x.subs('y', 3), self.x)
 154         self.assertEqual(self.pi.subs('x', 3), self.pi)
 155         self.assertEqual(self.expr.subs('x', -3), -2 * self.y)
 156         self.assertEqual(self.expr.subs([('x', self.y), ('y', self.x)]), 3 - self.x)
 157         self.assertEqual(self.expr.subs({'x': self.y, 'y': self.x}), 3 - self.x)
 158         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), -self.z + 3)
 159
 160     def test_fromstring(self):
 161         self.assertEqual(Expression.fromstring('x'), self.x)
 162         self.assertEqual(Expression.fromstring('-x'), -self.x)
 163         self.assertEqual(Expression.fromstring('22/7'), self.pi)
 164         self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
 165         self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
 166         self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
 167
 168     def test_str(self):
 169         self.assertEqual(str(Expression()), '0')
 170         self.assertEqual(str(self.x), 'x')
 171         self.assertEqual(str(-self.x), '-x')
 172         self.assertEqual(str(self.pi), '22/7')
 173         self.assertEqual(str(self.expr), 'x - 2*y + 3')
 174
 175     def test_repr(self):
 176         self.assertEqual(repr(self.x), "Symbol('x')")
 177         self.assertEqual(repr(self.one), 'Constant(1)')
 178         self.assertEqual(repr(self.pi), 'Constant(22, 7)')
 179         self.assertEqual(repr(self.x + self.one), "Expression('x + 1')")
 180         self.assertEqual(repr(self.expr), "Expression('x - 2*y + 3')")
 181
 182     @_requires_sympy
 183     def test_fromsympy(self):
 184         sp_x, sp_y = sympy.symbols('x y')
 185         self.assertEqual(Expression.fromsympy(sp_x), self.x)
 186         self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
 187         self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
 188         with self.assertRaises(ValueError):
 189             Expression.fromsympy(sp_x*sp_y)
 190
 191     @_requires_sympy
 192     def test_tosympy(self):
 193         sp_x, sp_y = sympy.symbols('x y')
 194         self.assertEqual(self.x.tosympy(), sp_x)
 195         self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
 196         self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
 197
 198
 199 class TestSymbol(unittest.TestCase):
 200
 201     def setUp(self):
 202         self.x = Symbol('x')
 203         self.y = Symbol('y')
 204
 205     def test_new(self):
 206         self.assertEqual(Symbol(' x '), self.x)
 207         self.assertEqual(Symbol(self.x), self.x)
 208         with self.assertRaises(TypeError):
 209             Symbol(1)
 210
 211     def test_name(self):
 212         self.assertEqual(self.x.name, 'x')
 213
 214     def test_issymbol(self):
 215         self.assertTrue(self.x.issymbol())
 216
 217     def test_fromstring(self):
 218         self.assertEqual(Symbol.fromstring('x'), self.x)
 219         with self.assertRaises(SyntaxError):
 220             Symbol.fromstring('1')
 221
 222     def test_str(self):
 223         self.assertEqual(str(self.x), 'x')
 224
 225     def test_repr(self):
 226         self.assertEqual(repr(self.x), "Symbol('x')")
 227
 228     @_requires_sympy
 229     def test_fromsympy(self):
 230         sp_x = sympy.Symbol('x')
 231         self.assertEqual(Symbol.fromsympy(sp_x), self.x)
 232         with self.assertRaises(TypeError):
 233             Symbol.fromsympy(sympy.Rational(22, 7))
 234         with self.assertRaises(TypeError):
 235             Symbol.fromsympy(2 * sp_x)
 236         with self.assertRaises(TypeError):
 237             Symbol.fromsympy(sp_x*sp_x)
 238
 239     def test_symbols(self):
 240         self.assertListEqual(list(symbols('x y')), [self.x, self.y])
 241         self.assertListEqual(list(symbols('x,y')), [self.x, self.y])
 242         self.assertListEqual(list(symbols(['x', 'y'])), [self.x, self.y])
 243
 244
 245 class TestConstant(unittest.TestCase):
 246
 247     def setUp(self):
 248         self.zero = Constant(0)
 249         self.one = Constant(1)
 250         self.pi = Constant(Fraction(22, 7))
 251
 252     def test_new(self):
 253         self.assertEqual(Constant(), self.zero)
 254         self.assertEqual(Constant(1), self.one)
 255         self.assertEqual(Constant(self.pi), self.pi)
 256         self.assertEqual(Constant('22/7'), self.pi)
 257
 258     def test_isconstant(self):
 259         self.assertTrue(self.zero.isconstant())
 260
 261     def test_bool(self):
 262         self.assertFalse(self.zero)
 263         self.assertTrue(self.pi)
 264
 265     def test_fromstring(self):
 266         self.assertEqual(Constant.fromstring('22/7'), self.pi)
 267         with self.assertRaises(ValueError):
 268             Constant.fromstring('a')
 269         with self.assertRaises(TypeError):
 270             Constant.fromstring(1)
 271
 272     def test_repr(self):
 273         self.assertEqual(repr(self.zero), 'Constant(0)')
 274         self.assertEqual(repr(self.one), 'Constant(1)')
 275         self.assertEqual(repr(self.pi), 'Constant(22, 7)')
 276
 277     @_requires_sympy
 278     def test_fromsympy(self):
 279         self.assertEqual(Constant.fromsympy(sympy.Rational(22, 7)), self.pi)
 280         with self.assertRaises(TypeError):
 281             Constant.fromsympy(sympy.Symbol('x'))