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 = Expression({'x': 1})
  14         self.y = Expression({'y': 1})
  15         self.z = Expression({'z': 1})
  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, Constant)
  24         self.assertNotIsInstance(self.x + self.pi, Symbol)
  25         self.assertNotIsInstance(self.x + self.pi, Constant)
  26         xx = Expression({'x': 2})
  27         self.assertNotIsInstance(xx, Symbol)
  28         with self.assertRaises(TypeError):
  29             Expression('x + y', 2)
  30         self.assertEqual(Expression({'x': 2}), Expression({self.x: 2}))
  31         with self.assertRaises(TypeError):
  32             Expression({0: 2})
  33         with self.assertRaises(TypeError):
  34             Expression({'x': '2'})
  35         self.assertEqual(Expression(constant=1), Expression(constant=self.one))
  36         self.assertEqual(Expression(constant='1'), Expression(constant=self.one))
  37         with self.assertRaises(ValueError):
  38             Expression(constant='a')
  39
  40     def test_coefficient(self):
  41         self.assertEqual(self.expr.coefficient('x'), 1)
  42         self.assertEqual(self.expr.coefficient('y'), -2)
  43         self.assertEqual(self.expr.coefficient(self.y), -2)
  44         self.assertEqual(self.expr.coefficient('z'), 0)
  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['x'], 1)
  52         self.assertEqual(self.expr['y'], -2)
  53         self.assertEqual(self.expr[self.y], -2)
  54         self.assertEqual(self.expr['z'], 0)
  55         with self.assertRaises(TypeError):
  56             self.expr[0]
  57         with self.assertRaises(TypeError):
  58             self.expr[self.expr]
  59
  60     def test_coefficients(self):
  61         self.assertCountEqual(self.expr.coefficients(), [('x', 1), ('y', -2)])
  62
  63     def test_constant(self):
  64         self.assertEqual(self.x.constant, 0)
  65         self.assertEqual(self.pi.constant, Fraction(22, 7))
  66         self.assertEqual(self.expr.constant, 3)
  67
  68     def test_symbols(self):
  69         self.assertCountEqual(self.x.symbols, ['x'])
  70         self.assertCountEqual(self.pi.symbols, [])
  71         self.assertCountEqual(self.expr.symbols, ['x', 'y'])
  72
  73     def test_dimension(self):
  74         self.assertEqual(self.x.dimension, 1)
  75         self.assertEqual(self.pi.dimension, 0)
  76         self.assertEqual(self.expr.dimension, 2)
  77
  78     def test_isconstant(self):
  79         self.assertFalse(self.x.isconstant())
  80         self.assertTrue(self.pi.isconstant())
  81         self.assertFalse(self.expr.isconstant())
  82
  83     def test_issymbol(self):
  84         self.assertTrue(self.x.issymbol())
  85         self.assertFalse(self.pi.issymbol())
  86         self.assertFalse(self.expr.issymbol())
  87
  88     def test_values(self):
  89         self.assertCountEqual(self.expr.values(), [1, -2, 3])
  90
  91     def test_bool(self):
  92         self.assertTrue(self.x)
  93         self.assertFalse(self.zero)
  94         self.assertTrue(self.pi)
  95         self.assertTrue(self.expr)
  96
  97     def test_pos(self):
  98         self.assertEqual(+self.expr, self.expr)
  99
 100     def test_neg(self):
 101         self.assertEqual(-self.expr, -self.x + 2*self.y - 3)
 102
 103     def test_add(self):
 104         self.assertEqual(self.x + Fraction(22, 7), self.x + self.pi)
 105         self.assertEqual(Fraction(22, 7) + self.x, self.x + self.pi)
 106         self.assertEqual(self.x + self.x, 2 * self.x)
 107         self.assertEqual(self.expr + 2*self.y, self.x + 3)
 108
 109     def test_sub(self):
 110         self.assertEqual(self.x - self.x, 0)
 111         self.assertEqual(self.expr - 3, self.x - 2*self.y)
 112         self.assertEqual(0 - self.x, -self.x)
 113
 114     def test_mul(self):
 115         self.assertEqual(self.pi * 7, 22)
 116         self.assertEqual(self.expr * 0, 0)
 117         self.assertEqual(0 * self.expr, 0)
 118         self.assertEqual(self.expr * 2, 2*self.x - 4*self.y + 6)
 119
 120     def test_truediv(self):
 121         with self.assertRaises(ZeroDivisionError):
 122             self.expr / 0
 123         self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 124
 125     def test_eq(self):
 126         self.assertEqual(self.expr, self.expr)
 127         self.assertNotEqual(self.x, self.y)
 128         self.assertEqual(self.zero, 0)
 129
 130     def test__toint(self):
 131         self.assertEqual((self.x + self.y/2 + self.z/3)._toint(),
 132                 6*self.x + 3*self.y + 2*self.z)
 133
 134     def test_subs(self):
 135         self.assertEqual(self.x.subs('x', 3), 3)
 136         self.assertEqual(self.x.subs('x', self.x), self.x)
 137         self.assertEqual(self.x.subs('x', self.y), self.y)
 138         self.assertEqual(self.x.subs('x', self.x + self.y), self.x + self.y)
 139         self.assertEqual(self.x.subs('y', 3), self.x)
 140         self.assertEqual(self.pi.subs('x', 3), self.pi)
 141         self.assertEqual(self.expr.subs('x', -3), -2 * self.y)
 142         self.assertEqual(self.expr.subs([('x', self.y), ('y', self.x)]), 3 - self.x)
 143         self.assertEqual(self.expr.subs({'x': self.z, 'y': self.z}), 3 - self.z)
 144         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
 145
 146     def test_fromstring(self):
 147         self.assertEqual(Expression.fromstring('x'), self.x)
 148         self.assertEqual(Expression.fromstring('-x'), -self.x)
 149         self.assertEqual(Expression.fromstring('22/7'), self.pi)
 150         self.assertEqual(Expression.fromstring('x - 2y + 3'), self.expr)
 151         self.assertEqual(Expression.fromstring('x - (3-1)y + 3'), self.expr)
 152         self.assertEqual(Expression.fromstring('x - 2*y + 3'), self.expr)
 153
 154     def test_str(self):
 155         self.assertEqual(str(Expression()), '0')
 156         self.assertEqual(str(self.x), 'x')
 157         self.assertEqual(str(-self.x), '-x')
 158         self.assertEqual(str(self.pi), '22/7')
 159         self.assertEqual(str(self.expr), 'x - 2*y + 3')
 160
 161     def test_repr(self):
 162         self.assertEqual(repr(self.x), "Symbol('x')")
 163         self.assertEqual(repr(self.one), 'Constant(1)')
 164         self.assertEqual(repr(self.pi), 'Constant(22, 7)')
 165         self.assertEqual(repr(self.x + self.one), "Expression('x + 1')")
 166         self.assertEqual(repr(self.expr), "Expression('x - 2*y + 3')")
 167
 168     @requires_sympy
 169     def test_fromsympy(self):
 170         import sympy
 171         sp_x, sp_y = sympy.symbols('x y')
 172         self.assertEqual(Expression.fromsympy(sp_x), self.x)
 173         self.assertEqual(Expression.fromsympy(sympy.Rational(22, 7)), self.pi)
 174         self.assertEqual(Expression.fromsympy(sp_x - 2*sp_y + 3), self.expr)
 175         with self.assertRaises(ValueError):
 176             Expression.fromsympy(sp_x*sp_y)
 177
 178     @requires_sympy
 179     def test_tosympy(self):
 180         import sympy
 181         sp_x, sp_y = sympy.symbols('x y')
 182         self.assertEqual(self.x.tosympy(), sp_x)
 183         self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
 184         self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
 185
 186
 187 class TestSymbol(unittest.TestCase):
 188
 189     def setUp(self):
 190         self.x = Symbol('x')
 191         self.y = Symbol('y')
 192
 193     def test_new(self):
 194         self.assertEqual(Symbol(' x '), self.x)
 195         self.assertEqual(Symbol(self.x), self.x)
 196         with self.assertRaises(TypeError):
 197             Symbol(1)
 198
 199     def test_name(self):
 200         self.assertEqual(self.x.name, 'x')
 201
 202     def test_issymbol(self):
 203         self.assertTrue(self.x.issymbol())
 204
 205     def test_fromstring(self):
 206         self.assertEqual(Symbol.fromstring('x'), self.x)
 207         with self.assertRaises(SyntaxError):
 208             Symbol.fromstring('1')
 209
 210     def test_str(self):
 211         self.assertEqual(str(self.x), 'x')
 212
 213     def test_repr(self):
 214         self.assertEqual(repr(self.x), "Symbol('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 TestConstant(unittest.TestCase):
 235
 236     def setUp(self):
 237         self.zero = Constant(0)
 238         self.one = Constant(1)
 239         self.pi = Constant(Fraction(22, 7))
 240
 241     def test_new(self):
 242         self.assertEqual(Constant(), self.zero)
 243         self.assertEqual(Constant(1), self.one)
 244         self.assertEqual(Constant(self.pi), self.pi)
 245         self.assertEqual(Constant('22/7'), self.pi)
 246
 247     def test_isconstant(self):
 248         self.assertTrue(self.zero.isconstant())
 249
 250     def test_bool(self):
 251         self.assertFalse(self.zero)
 252         self.assertTrue(self.pi)
 253
 254     def test_fromstring(self):
 255         self.assertEqual(Constant.fromstring('22/7'), self.pi)
 256         with self.assertRaises(ValueError):
 257             Constant.fromstring('a')
 258         with self.assertRaises(TypeError):
 259             Constant.fromstring(1)
 260
 261     def test_repr(self):
 262         self.assertEqual(repr(self.zero), 'Constant(0)')
 263         self.assertEqual(repr(self.one), 'Constant(1)')
 264         self.assertEqual(repr(self.pi), 'Constant(22, 7)')
 265
 266     @requires_sympy
 267     def test_fromsympy(self):
 268         import sympy
 269         self.assertEqual(Constant.fromsympy(sympy.Rational(22, 7)), self.pi)
 270         with self.assertRaises(TypeError):
 271             Constant.fromsympy(sympy.Symbol('x'))