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(self.x, Symbol)
  23         self.assertIsInstance(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.assertCountEqual(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.assertCountEqual(self.x.symbols, [self.x])
  71         self.assertCountEqual(self.pi.symbols, [])
  72         self.assertCountEqual(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.assertCountEqual(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
 121     def test_truediv(self):
 122         with self.assertRaises(ZeroDivisionError):
 123             self.expr / 0
 124         self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 125
 126     def test_eq(self):
 127         self.assertEqual(self.expr, self.expr)
 128         self.assertNotEqual(self.x, self.y)
 129         self.assertEqual(self.zero, 0)
 130
 131     def test_scaleint(self):
 132         self.assertEqual((self.x + self.y/2 + self.z/3).scaleint(),
 133                 6*self.x + 3*self.y + 2*self.z)
 134
 135     def test_subs(self):
 136         self.assertEqual(self.x.subs(self.x, 3), 3)
 137         self.assertEqual(self.x.subs(self.x, self.x), self.x)
 138         self.assertEqual(self.x.subs(self.x, self.y), self.y)
 139         self.assertEqual(self.x.subs(self.x, self.x + self.y), self.x + self.y)
 140         self.assertEqual(self.x.subs(self.y, 3), self.x)
 141         self.assertEqual(self.pi.subs(self.x, 3), self.pi)
 142         self.assertEqual(self.expr.subs(self.x, -3), -2 * self.y)
 143         self.assertEqual(self.expr.subs([(self.x, self.y), (self.y, self.x)]), 3 - self.x)
 144         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
 145         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
 146         with self.assertRaises(TypeError):
 147             self.x.subs('x', 3)
 148         with self.assertRaises(TypeError):
 149             self.expr.subs([('x', self.z), ('y', self.z)])
 150         with self.assertRaises(TypeError):
 151             self.expr.subs({'x': self.z, 'y': self.z})
 152         with self.assertRaises(TypeError):
 153             self.expr.subs(self.x, 'x')
 154
 155     def test_fromstring(self):
 156         self.assertEqual(Expression.fromstring('x'), self.x)
 157         self.assertEqual(Expression.fromstring('-x'), -self.x)
 158         self.assertEqual(Expression.fromstring('22/7'), self.pi)
 159         self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
 160         self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
 161         self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
 162
 163     def test_repr(self):
 164         self.assertEqual(str(Expression()), '0')
 165         self.assertEqual(str(self.x), 'x')
 166         self.assertEqual(str(-self.x), '-x')
 167         self.assertEqual(str(self.pi), '22/7')
 168         self.assertEqual(str(self.expr), 'x - 2*y + 3')
 169
 170     @requires_sympy
 171     def test_fromsympy(self):
 172         import sympy
 173         sp_x, sp_y = sympy.symbols('x y')
 174         self.assertEqual(Expression.fromsympy(sp_x), self.x)
 175         self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
 176         self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
 177         with self.assertRaises(ValueError):
 178             Expression.fromsympy(sp_x*sp_y)
 179
 180     @requires_sympy
 181     def test_tosympy(self):
 182         import sympy
 183         sp_x, sp_y = sympy.symbols('x y')
 184         self.assertEqual(self.x.tosympy(), sp_x)
 185         self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
 186         self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
 187
 188
 189 class TestSymbol(unittest.TestCase):
 190
 191     def setUp(self):
 192         self.x = Symbol('x')
 193         self.y = Symbol('y')
 194
 195     def test_new(self):
 196         self.assertEqual(Symbol(' x '), self.x)
 197         with self.assertRaises(TypeError):
 198             Symbol(self.x)
 199         with self.assertRaises(TypeError):
 200             Symbol(1)
 201
 202     def test_name(self):
 203         self.assertEqual(self.x.name, 'x')
 204
 205     def test_issymbol(self):
 206         self.assertTrue(self.x.issymbol())
 207
 208     def test_fromstring(self):
 209         self.assertEqual(Symbol.fromstring('x'), self.x)
 210         with self.assertRaises(SyntaxError):
 211             Symbol.fromstring('1')
 212
 213     def test_repr(self):
 214         self.assertEqual(str(self.x), 'x')
 215
 216     @requires_sympy
 217     def test_fromsympy(self):
 218         import sympy
 219         sp_x = sympy.Symbol('x')
 220         self.assertEqual(Symbol.fromsympy(sp_x), self.x)
 221         with self.assertRaises(TypeError):
 222             Symbol.fromsympy(sympy.Rational(22, 7))
 223         with self.assertRaises(TypeError):
 224             Symbol.fromsympy(2 * sp_x)
 225         with self.assertRaises(TypeError):
 226             Symbol.fromsympy(sp_x*sp_x)
 227
 228     def test_symbols(self):
 229         self.assertListEqual(list(symbols('x y')), [self.x, self.y])
 230         self.assertListEqual(list(symbols('x,y')), [self.x, self.y])
 231         self.assertListEqual(list(symbols(['x', 'y'])), [self.x, self.y])
 232
 233
 234 class TestDummy(unittest.TestCase):
 235
 236     def setUp(self):
 237         self.x = Dummy('x')
 238
 239     def test_new(self):
 240         self.assertEqual(self.x.name, 'x')
 241         self.assertTrue(Dummy().name.startswith('Dummy'))
 242
 243     def test_eq(self):
 244         self.assertEqual(self.x, self.x)
 245         self.assertNotEqual(self.x, Symbol('x'))
 246         self.assertNotEqual(Symbol('x'), self.x)
 247         self.assertNotEqual(self.x, Dummy('x'))
 248         self.assertNotEqual(Dummy(), Dummy())
 249
 250
 251 class TestRational(unittest.TestCase):
 252
 253     def setUp(self):
 254         self.zero = Rational(0)
 255         self.one = Rational(1)
 256         self.pi = Rational(Fraction(22, 7))
 257
 258     def test_new(self):
 259         self.assertEqual(Rational(), self.zero)
 260         self.assertEqual(Rational(1), self.one)
 261         self.assertEqual(Rational(self.pi), self.pi)
 262         self.assertEqual(Rational('22/7'), self.pi)
 263
 264     def test_isconstant(self):
 265         self.assertTrue(self.zero.isconstant())
 266
 267     def test_bool(self):
 268         self.assertFalse(self.zero)
 269         self.assertTrue(self.pi)
 270
 271     def test_fromstring(self):
 272         self.assertEqual(Rational.fromstring('22/7'), self.pi)
 273         with self.assertRaises(ValueError):
 274             Rational.fromstring('a')
 275         with self.assertRaises(TypeError):
 276             Rational.fromstring(1)
 277
 278     def test_repr(self):
 279         self.assertEqual(repr(self.zero), '0')
 280         self.assertEqual(repr(self.one), '1')
 281         self.assertEqual(repr(self.pi), '22/7')
 282
 283     @requires_sympy
 284     def test_fromsympy(self):
 285         import sympy
 286         self.assertEqual(Rational.fromsympy(sympy.Rational(22, 7)), self.pi)
 287         with self.assertRaises(TypeError):
 288             Rational.fromsympy(sympy.Symbol('x'))