linpy/tests/test_linexprs.py

   1 # Copyright 2014 MINES ParisTech
   2 #
   3 # This file is part of LinPy.
   4 #
   5 # LinPy is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # LinPy is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with LinPy.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import unittest
  19
  20 from fractions import Fraction
  21
  22 from ..linexprs import Dummy, LinExpr, Rational, Symbol, symbols
  23 from .libhelper import requires_sympy
  24
  25
  26 class TestLinExpr(unittest.TestCase):
  27
  28     def setUp(self):
  29         self.x = Symbol('x')
  30         self.y = Symbol('y')
  31         self.z = Symbol('z')
  32         self.zero = LinExpr(constant=0)
  33         self.one = LinExpr(constant=1)
  34         self.pi = LinExpr(constant=Fraction(22, 7))
  35         self.expr = self.x - 2*self.y + 3
  36
  37     def test_new(self):
  38         self.assertIsInstance(LinExpr(coefficients={self.x: 1}), Symbol)
  39         self.assertIsInstance(LinExpr(constant=self.pi), Rational)
  40         self.assertNotIsInstance(self.x + self.pi, Symbol)
  41         self.assertNotIsInstance(self.x + self.pi, Rational)
  42         xx = LinExpr({self.x: 2})
  43         self.assertNotIsInstance(xx, Symbol)
  44         with self.assertRaises(TypeError):
  45             LinExpr('x + y', 2)
  46         with self.assertRaises(TypeError):
  47             LinExpr({0: 2})
  48         with self.assertRaises(TypeError):
  49             LinExpr({'x': '2'})
  50         self.assertEqual(LinExpr(constant=1), LinExpr(constant=self.one))
  51         self.assertEqual(LinExpr(constant='1'), LinExpr(constant=self.one))
  52         with self.assertRaises(ValueError):
  53             LinExpr(constant='a')
  54
  55     def test_coefficient(self):
  56         self.assertEqual(self.expr.coefficient(self.x), 1)
  57         self.assertEqual(self.expr.coefficient(self.y), -2)
  58         self.assertEqual(self.expr.coefficient(self.z), 0)
  59         with self.assertRaises(TypeError):
  60             self.expr.coefficients('x')
  61         with self.assertRaises(TypeError):
  62             self.expr.coefficient(0)
  63         with self.assertRaises(TypeError):
  64             self.expr.coefficient(self.expr)
  65
  66     def test_getitem(self):
  67         self.assertEqual(self.expr[self.x], 1)
  68         self.assertEqual(self.expr[self.y], -2)
  69         self.assertEqual(self.expr[self.z], 0)
  70         with self.assertRaises(TypeError):
  71             self.assertEqual(self.expr['x'], 1)
  72         with self.assertRaises(TypeError):
  73             self.expr[0]
  74         with self.assertRaises(TypeError):
  75             self.expr[self.expr]
  76
  77     def test_coefficients(self):
  78         self.assertListEqual(list(self.expr.coefficients()),
  79                              [(self.x, 1), (self.y, -2)])
  80
  81     def test_constant(self):
  82         self.assertEqual(self.x.constant, 0)
  83         self.assertEqual(self.pi.constant, Fraction(22, 7))
  84         self.assertEqual(self.expr.constant, 3)
  85
  86     def test_symbols(self):
  87         self.assertTupleEqual(self.x.symbols, (self.x,))
  88         self.assertTupleEqual(self.pi.symbols, ())
  89         self.assertTupleEqual(self.expr.symbols, (self.x, self.y))
  90
  91     def test_dimension(self):
  92         self.assertEqual(self.x.dimension, 1)
  93         self.assertEqual(self.pi.dimension, 0)
  94         self.assertEqual(self.expr.dimension, 2)
  95
  96     def test_isconstant(self):
  97         self.assertFalse(self.x.isconstant())
  98         self.assertTrue(self.pi.isconstant())
  99         self.assertFalse(self.expr.isconstant())
 100
 101     def test_issymbol(self):
 102         self.assertTrue(self.x.issymbol())
 103         self.assertFalse(self.pi.issymbol())
 104         self.assertFalse(self.expr.issymbol())
 105
 106     def test_values(self):
 107         self.assertListEqual(list(self.expr.values()), [1, -2, 3])
 108
 109     def test_bool(self):
 110         self.assertTrue(self.x)
 111         self.assertFalse(self.zero)
 112         self.assertTrue(self.pi)
 113         self.assertTrue(self.expr)
 114
 115     def test_pos(self):
 116         self.assertEqual(+self.expr, self.expr)
 117
 118     def test_neg(self):
 119         self.assertEqual(-self.expr, -self.x + 2*self.y - 3)
 120
 121     def test_add(self):
 122         self.assertEqual(self.x + Fraction(22, 7), self.x + self.pi)
 123         self.assertEqual(Fraction(22, 7) + self.x, self.x + self.pi)
 124         self.assertEqual(self.x + self.x, 2 * self.x)
 125         self.assertEqual(self.expr + 2*self.y, self.x + 3)
 126
 127     def test_sub(self):
 128         self.assertEqual(self.x - self.x, 0)
 129         self.assertEqual(self.expr - 3, self.x - 2*self.y)
 130         self.assertEqual(0 - self.x, -self.x)
 131
 132     def test_mul(self):
 133         self.assertEqual(self.pi * 7, 22)
 134         self.assertEqual(self.expr * 0, 0)
 135         self.assertEqual(0 * self.expr, 0)
 136         self.assertEqual(self.expr * 2, 2*self.x - 4*self.y + 6)
 137         with self.assertRaises(TypeError):
 138             self.x * self.x
 139
 140     def test_truediv(self):
 141         with self.assertRaises(ZeroDivisionError):
 142             self.expr / 0
 143         self.assertEqual(self.expr / 2, self.x / 2 - self.y + Fraction(3, 2))
 144         with self.assertRaises(TypeError):
 145             self.x / self.x
 146
 147     def test_eq(self):
 148         self.assertEqual(self.expr, self.expr)
 149         self.assertNotEqual(self.x, self.y)
 150         self.assertEqual(self.zero, 0)
 151
 152     def test_scaleint(self):
 153         self.assertEqual((self.x + self.y/2 + self.z/3).scaleint(),
 154                          6*self.x + 3*self.y + 2*self.z)
 155
 156     def test_subs(self):
 157         self.assertEqual(self.x.subs(self.x, 3), 3)
 158         self.assertEqual(self.x.subs(self.x, self.x), self.x)
 159         self.assertEqual(self.x.subs(self.x, self.y), self.y)
 160         self.assertEqual(self.x.subs(self.x, self.x + self.y), self.x + self.y)
 161         self.assertEqual(self.x.subs(self.y, 3), self.x)
 162         self.assertEqual(self.pi.subs(self.x, 3), self.pi)
 163         self.assertEqual(self.expr.subs(self.x, -3), -2 * self.y)
 164         self.assertEqual(self.expr.subs([(self.x, self.y), (self.y, self.x)]),
 165                          -2*self.x + self.y + 3)
 166         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}),
 167                          3 - self.z)
 168         self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}),
 169                          3 - self.z)
 170         with self.assertRaises(TypeError):
 171             self.x.subs('x', 3)
 172         with self.assertRaises(TypeError):
 173             self.expr.subs([('x', self.z), ('y', self.z)])
 174         with self.assertRaises(TypeError):
 175             self.expr.subs({'x': self.z, 'y': self.z})
 176         with self.assertRaises(TypeError):
 177             self.expr.subs(self.x, 'x')
 178
 179     def test_fromstring(self):
 180         self.assertEqual(LinExpr.fromstring('x'), self.x)
 181         self.assertEqual(LinExpr.fromstring('-x'), -self.x)
 182         self.assertEqual(LinExpr.fromstring('22/7'), self.pi)
 183         self.assertEqual(LinExpr.fromstring('x - 2y + 3'), self.expr)
 184         self.assertEqual(LinExpr.fromstring('x - (3-1)y + 3'), self.expr)
 185         self.assertEqual(LinExpr.fromstring('x - 2*y + 3'), self.expr)
 186
 187     def test_repr(self):
 188         self.assertEqual(str(LinExpr()), '0')
 189         self.assertEqual(str(self.x), 'x')
 190         self.assertEqual(str(-self.x), '-x')
 191         self.assertEqual(str(self.pi), '22/7')
 192         self.assertEqual(str(self.expr), 'x - 2*y + 3')
 193
 194     @requires_sympy
 195     def test_fromsympy(self):
 196         import sympy
 197         sp_x, sp_y = sympy.symbols('x y')
 198         self.assertEqual(LinExpr.fromsympy(sp_x), self.x)
 199         self.assertEqual(LinExpr.fromsympy(sympy.Rational(22, 7)), self.pi)
 200         self.assertEqual(LinExpr.fromsympy(sp_x - 2*sp_y + 3), self.expr)
 201         with self.assertRaises(TypeError):
 202             LinExpr.fromsympy(sp_x*sp_y)
 203
 204     @requires_sympy
 205     def test_tosympy(self):
 206         import sympy
 207         sp_x, sp_y = sympy.symbols('x y')
 208         self.assertEqual(self.x.tosympy(), sp_x)
 209         self.assertEqual(self.pi.tosympy(), sympy.Rational(22, 7))
 210         self.assertEqual(self.expr.tosympy(), sp_x - 2*sp_y + 3)
 211
 212
 213 class TestSymbol(unittest.TestCase):
 214
 215     def setUp(self):
 216         self.x = Symbol('x')
 217         self.y = Symbol('y')
 218
 219     def test_new(self):
 220         self.assertEqual(Symbol('x'), self.x)
 221         with self.assertRaises(TypeError):
 222             Symbol(self.x)
 223         with self.assertRaises(TypeError):
 224             Symbol(1)
 225         with self.assertRaises(SyntaxError):
 226             Symbol('1')
 227         with self.assertRaises(SyntaxError):
 228             Symbol('x.1')
 229         with self.assertRaises(SyntaxError):
 230             Symbol('x 1')
 231         Symbol('_')
 232         Symbol('_x')
 233         Symbol('x_1')
 234
 235     def test_name(self):
 236         self.assertEqual(self.x.name, 'x')
 237
 238     def test_issymbol(self):
 239         self.assertTrue(self.x.issymbol())
 240
 241     def test_fromstring(self):
 242         self.assertEqual(Symbol.fromstring('x'), self.x)
 243         with self.assertRaises(SyntaxError):
 244             Symbol.fromstring('1')
 245
 246     def test_repr(self):
 247         self.assertEqual(str(self.x), 'x')
 248
 249     @requires_sympy
 250     def test_fromsympy(self):
 251         import sympy
 252         sp_x = sympy.Symbol('x')
 253         self.assertEqual(Symbol.fromsympy(sp_x), self.x)
 254         with self.assertRaises(TypeError):
 255             Symbol.fromsympy(sympy.Rational(22, 7))
 256         with self.assertRaises(TypeError):
 257             Symbol.fromsympy(2 * sp_x)
 258         with self.assertRaises(TypeError):
 259             Symbol.fromsympy(sp_x*sp_x)
 260
 261
 262 class TestDummy(unittest.TestCase):
 263
 264     def setUp(self):
 265         self.x = Dummy('x')
 266
 267     def test_new(self):
 268         self.assertEqual(self.x.name, 'x')
 269         self.assertTrue(Dummy().name.startswith('Dummy'))
 270
 271     def test_eq(self):
 272         self.assertEqual(self.x, self.x)
 273         self.assertNotEqual(self.x, Symbol('x'))
 274         self.assertNotEqual(Symbol('x'), self.x)
 275         self.assertNotEqual(self.x, Dummy('x'))
 276         self.assertNotEqual(Dummy(), Dummy())
 277
 278     def test_repr(self):
 279         self.assertEqual(repr(self.x), '_x')
 280         dummy1 = Dummy()
 281         dummy2 = Dummy()
 282         self.assertTrue(repr(dummy1).startswith('_Dummy_'))
 283         self.assertNotEqual(repr(dummy1), repr(dummy2))
 284
 285
 286 class TestSymbols(unittest.TestCase):
 287
 288     def setUp(self):
 289         self.x = Symbol('x')
 290         self.y = Symbol('y')
 291
 292     def test(self):
 293         self.assertTupleEqual(symbols('x y'), (self.x, self.y))
 294         self.assertTupleEqual(symbols('x,y'), (self.x, self.y))
 295         self.assertTupleEqual(symbols(['x', 'y']), (self.x, self.y))
 296         with self.assertRaises(TypeError):
 297             symbols(1)
 298         with self.assertRaises(TypeError):
 299             symbols(['a', 1])
 300
 301
 302 class TestRational(unittest.TestCase):
 303
 304     def setUp(self):
 305         self.zero = Rational(0)
 306         self.one = Rational(1)
 307         self.pi = Rational(22, 7)
 308
 309     def test_new(self):
 310         self.assertEqual(Rational(), self.zero)
 311         self.assertEqual(Rational(1), self.one)
 312         self.assertEqual(Rational(self.pi), self.pi)
 313         self.assertEqual(Rational('22/7'), self.pi)
 314
 315     def test_hash(self):
 316         self.assertEqual(hash(self.one), hash(1))
 317         self.assertEqual(hash(self.pi), hash(Fraction(22, 7)))
 318
 319     def test_isconstant(self):
 320         self.assertTrue(self.zero.isconstant())
 321
 322     def test_bool(self):
 323         self.assertFalse(self.zero)
 324         self.assertTrue(self.pi)
 325
 326     def test_repr(self):
 327         self.assertEqual(repr(self.zero), '0')
 328         self.assertEqual(repr(self.one), '1')
 329         self.assertEqual(repr(self.pi), '22/7')
 330
 331     @requires_sympy
 332     def test_fromsympy(self):
 333         import sympy
 334         self.assertEqual(Rational.fromsympy(sympy.Rational(22, 7)), self.pi)
 335         with self.assertRaises(TypeError):
 336             Rational.fromsympy(sympy.Symbol('x'))