pypol/tests/test_linexprs.py

   1 import functools
   2 import unittest
   3
   4 from fractions import Fraction
   5
   6 from ..linexprs import *
   7 from .libhelper import requires_sympy
   8
   9
  10 class TestExpression(unittest.TestCase):
  11
  12     def setUp(self):
  13         self.x = Symbol('x')
  14         self.y = Symbol('y')
  15         self.z = Symbol('z')
  16         self.zero = Expression(constant=0)
  17         self.one = Expression(constant=1)
  18         self.pi = Expression(constant=Fraction(22, 7))
  19         self.expr = self.x - 2*self.y + 3
  20
  21     def test_new(self):
  22         self.assertIsInstance(Expression(coefficients={self.x: 1}), Symbol)
  23         self.assertIsInstance(Expression(constant=self.pi), Rational)
  24         self.assertNotIsInstance(self.x + self.pi, Symbol)
  25         self.assertNotIsInstance(self.x + self.pi, Rational)
  26         xx = Expression({self.x: 2})
  27         self.assertNotIsInstance(xx, Symbol)
  28         with self.assertRaises(TypeError):
  29             Expression('x + y', 2)
  30         with self.assertRaises(TypeError):
  31             Expression({0: 2})
  32         with self.assertRaises(TypeError):
  33             Expression({'x': '2'})
  34         self.assertEqual(Expression(constant=1), Expression(constant=self.one))
  35         self.assertEqual(Expression(constant='1'), Expression(constant=self.one))
  36         with self.assertRaises(ValueError):
  37             Expression(constant='a')
  38
  39     def test_coefficient(self):
  40         self.assertEqual(self.expr.coefficient(self.x), 1)
  41         self.assertEqual(self.expr.coefficient(self.y), -2)
  42         self.assertEqual(self.expr.coefficient(self.z), 0)
  43         with self.assertRaises(TypeError):
  44             self.expr.coefficients('x')
  45         with self.assertRaises(TypeError):
  46             self.expr.coefficient(0)
  47         with self.assertRaises(TypeError):
  48             self.expr.coefficient(self.expr)
  49
  50     def test_getitem(self):
  51         self.assertEqual(self.expr[self.x], 1)
  52         self.assertEqual(self.expr[self.y], -2)
  53         self.assertEqual(self.expr[self.z], 0)
  54         with self.assertRaises(TypeError):
  55             self.assertEqual(self.expr['x'], 1)
  56         with self.assertRaises(TypeError):
  57             self.expr[0]
  58         with self.assertRaises(TypeError):
  59             self.expr[self.expr]
  60
  61     def test_coefficients(self):
  62         self.assertListEqual(list(self.expr.coefficients()), [(self.x, 1), (self.y, -2)])
  63
  64     def test_constant(self):
  65         self.assertEqual(self.x.constant, 0)
  66         self.assertEqual(self.pi.constant, Fraction(22, 7))
  67         self.assertEqual(self.expr.constant, 3)
  68
  69     def test_symbols(self):
  70         self.assertTupleEqual(self.x.symbols, (self.x,))
  71         self.assertTupleEqual(self.pi.symbols, ())
  72         self.assertTupleEqual(self.expr.symbols, (self.x, self.y))
  73
  74     def test_dimension(self):
  75         self.assertEqual(self.x.dimension, 1)
  76         self.assertEqual(self.pi.dimension, 0)
  77         self.assertEqual(self.expr.dimension, 2)
  78
  79     def test_isconstant(self):
  80         self.assertFalse(self.x.isconstant())
  81         self.assertTrue(self.pi.isconstant())
  82         self.assertFalse(self.expr.isconstant())
  83
  84     def test_issymbol(self):
  85         self.assertTrue(self.x.issymbol())
  86         self.assertFalse(self.pi.issymbol())
  87         self.assertFalse(self.expr.issymbol())
  88
  89     def test_values(self):
  90         self.assertListEqual(list(self.expr.values()), [1, -2, 3])
  91
  92     def test_bool(self):
  93         self.assertTrue(self.x)
  94         self.assertFalse(self.zero)
  95         self.assertTrue(self.pi)
  96         self.assertTrue(self.expr)
  97
  98     def test_pos(self):
  99         self.assertEqual(+self.expr, self.expr)
 100
 101     def test_neg(self):
 102         self.assertEqual(-self.expr, -self.x + 2*self.y - 3)
 103
 104     def test_add(self):
 105         self.assertEqual(self.x + Fraction(22, 7), self.x + self.pi)
 106         self.assertEqual(Fraction(22, 7) + self.x, self.x + self.pi)
 107         self.assertEqual(self.x + self.x, 2 * self.x)
 108         self.assertEqual(self.expr + 2*self.y, self.x + 3)
 109
 110     def test_sub(self):
 111         self.assertEqual(self.x - self.x, 0)
 112         self.assertEqual(self.expr - 3, self.x - 2*self.y)
 113         self.assertEqual(0 - self.x, -self.x)
 114
 115     def test_mul(self):
 116         self.assertEqual(self.pi * 7, 22)
 117         self.assertEqual(self.expr * 0, 0)
 118         self.assertEqual(0 * self.expr, 0)
 119         self.assertEqual(self.expr * 2, 2*self.x - 4*self.y + 6)
 120         with self.assertRaises(TypeError):
 121             self.x * self.x
 122
 123     def test_truediv(self):
 124         with self.assertRaises(ZeroDivisionError):
 125             self.expr / 0
 126         self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 127         with self.assertRaises(TypeError):
 128             self.x / self.x
 129
 130     def test_eq(self):
 131         self.assertEqual(self.expr, self.expr)
 132         self.assertNotEqual(self.x, self.y)
 133         self.assertEqual(self.zero, 0)
 134
 135     def test_scaleint(self):
 136         self.assertEqual((self.x + self.y/2 + self.z/3).scaleint(),
 137                 6*self.x + 3*self.y + 2*self.z)
 138
 139     def test_subs(self):
 140         self.assertEqual(self.x.subs(self.x, 3), 3)
 141         self.assertEqual(self.x.subs(self.x, self.x), self.x)
 142         self.assertEqual(self.x.subs(self.x, self.y), self.y)
 143         self.assertEqual(self.x.subs(self.x, self.x + self.y), self.x + self.y)
 144         self.assertEqual(self.x.subs(self.y, 3), self.x)
 145         self.assertEqual(self.pi.subs(self.x, 3), self.pi)
 146         self.assertEqual(self.expr.subs(self.x, -3), -2 * self.y)
 147         self.assertEqual(self.expr.subs([(self.x, self.y), (self.y, self.x)]), 3 - self.x)
 148         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
 149         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
 150         with self.assertRaises(TypeError):
 151             self.x.subs('x', 3)
 152         with self.assertRaises(TypeError):
 153             self.expr.subs([('x', self.z), ('y', self.z)])
 154         with self.assertRaises(TypeError):
 155             self.expr.subs({'x': self.z, 'y': self.z})
 156         with self.assertRaises(TypeError):
 157             self.expr.subs(self.x, 'x')
 158
 159     def test_fromstring(self):
 160         self.assertEqual(Expression.fromstring('x'), self.x)
 161         self.assertEqual(Expression.fromstring('-x'), -self.x)
 162         self.assertEqual(Expression.fromstring('22/7'), self.pi)
 163         self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
 164         self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
 165         self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
 166
 167     def test_repr(self):
 168         self.assertEqual(str(Expression()), '0')
 169         self.assertEqual(str(self.x), 'x')
 170         self.assertEqual(str(-self.x), '-x')
 171         self.assertEqual(str(self.pi), '22/7')
 172         self.assertEqual(str(self.expr), 'x - 2*y + 3')
 173
 174     @requires_sympy
 175     def test_fromsympy(self):
 176         import sympy
 177         sp_x, sp_y = sympy.symbols('x y')
 178         self.assertEqual(Expression.fromsympy(sp_x), self.x)
 179         self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
 180         self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
 181         with self.assertRaises(ValueError):
 182             Expression.fromsympy(sp_x*sp_y)
 183
 184     @requires_sympy
 185     def test_tosympy(self):
 186         import sympy
 187         sp_x, sp_y = sympy.symbols('x y')
 188         self.assertEqual(self.x.tosympy(), sp_x)
 189         self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
 190         self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
 191
 192
 193 class TestSymbol(unittest.TestCase):
 194
 195     def setUp(self):
 196         self.x = Symbol('x')
 197         self.y = Symbol('y')
 198
 199     def test_new(self):
 200         self.assertEqual(Symbol(' x '), self.x)
 201         with self.assertRaises(TypeError):
 202             Symbol(self.x)
 203         with self.assertRaises(TypeError):
 204             Symbol(1)
 205
 206     def test_name(self):
 207         self.assertEqual(self.x.name, 'x')
 208
 209     def test_issymbol(self):
 210         self.assertTrue(self.x.issymbol())
 211
 212     def test_fromstring(self):
 213         self.assertEqual(Symbol.fromstring('x'), self.x)
 214         with self.assertRaises(SyntaxError):
 215             Symbol.fromstring('1')
 216
 217     def test_repr(self):
 218         self.assertEqual(str(self.x), 'x')
 219
 220     @requires_sympy
 221     def test_fromsympy(self):
 222         import sympy
 223         sp_x = sympy.Symbol('x')
 224         self.assertEqual(Symbol.fromsympy(sp_x), self.x)
 225         with self.assertRaises(TypeError):
 226             Symbol.fromsympy(sympy.Rational(22, 7))
 227         with self.assertRaises(TypeError):
 228             Symbol.fromsympy(2 * sp_x)
 229         with self.assertRaises(TypeError):
 230             Symbol.fromsympy(sp_x*sp_x)
 231
 232
 233 class TestDummy(unittest.TestCase):
 234
 235     def setUp(self):
 236         self.x = Dummy('x')
 237
 238     def test_new(self):
 239         self.assertEqual(self.x.name, 'x')
 240         self.assertTrue(Dummy().name.startswith('Dummy'))
 241
 242     def test_eq(self):
 243         self.assertEqual(self.x, self.x)
 244         self.assertNotEqual(self.x, Symbol('x'))
 245         self.assertNotEqual(Symbol('x'), self.x)
 246         self.assertNotEqual(self.x, Dummy('x'))
 247         self.assertNotEqual(Dummy(), Dummy())
 248
 249     def test_repr(self):
 250         self.assertEqual(repr(self.x), '_x')
 251         dummy1 = Dummy()
 252         dummy2 = Dummy()
 253         self.assertTrue(repr(dummy1).startswith('_Dummy_'))
 254         self.assertNotEqual(repr(dummy1), repr(dummy2))
 255
 256
 257 class TestSymbols(unittest.TestCase):
 258
 259     def setUp(self):
 260         self.x = Symbol('x')
 261         self.y = Symbol('y')
 262
 263     def test(self):
 264         self.assertTupleEqual(symbols('x y'), (self.x, self.y))
 265         self.assertTupleEqual(symbols('x,y'), (self.x, self.y))
 266         self.assertTupleEqual(symbols(['x', 'y']), (self.x, self.y))
 267         with self.assertRaises(TypeError):
 268             symbols(1)
 269         with self.assertRaises(TypeError):
 270             symbols(['a', 1])
 271
 272
 273 class TestRational(unittest.TestCase):
 274
 275     def setUp(self):
 276         self.zero = Rational(0)
 277         self.one = Rational(1)
 278         self.pi = Rational(22, 7)
 279
 280     def test_new(self):
 281         self.assertEqual(Rational(), self.zero)
 282         self.assertEqual(Rational(1), self.one)
 283         self.assertEqual(Rational(self.pi), self.pi)
 284         self.assertEqual(Rational('22/7'), self.pi)
 285
 286     def test_hash(self):
 287         self.assertEqual(hash(self.one), hash(1))
 288         self.assertEqual(hash(self.pi), hash(Fraction(22, 7)))
 289
 290     def test_isconstant(self):
 291         self.assertTrue(self.zero.isconstant())
 292
 293     def test_bool(self):
 294         self.assertFalse(self.zero)
 295         self.assertTrue(self.pi)
 296
 297     def test_repr(self):
 298         self.assertEqual(repr(self.zero), '0')
 299         self.assertEqual(repr(self.one), '1')
 300         self.assertEqual(repr(self.pi), '22/7')
 301
 302     @requires_sympy
 303     def test_fromsympy(self):
 304         import sympy
 305         self.assertEqual(Rational.fromsympy(sympy.Rational(22, 7)), self.pi)
 306         with self.assertRaises(TypeError):
 307             Rational.fromsympy(sympy.Symbol('x'))