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| from sympy.core.mul import Mul | |
| from sympy.core.numbers import Rational | |
| from sympy.core.singleton import S | |
| from sympy.core.symbol import (Symbol, symbols) | |
| from sympy.physics.units import Quantity, length, meter, W | |
| from sympy.physics.units.prefixes import PREFIXES, Prefix, prefix_unit, kilo, \ | |
| kibi | |
| from sympy.physics.units.systems import SI | |
| x = Symbol('x') | |
| def test_prefix_operations(): | |
| m = PREFIXES['m'] | |
| k = PREFIXES['k'] | |
| M = PREFIXES['M'] | |
| dodeca = Prefix('dodeca', 'dd', 1, base=12) | |
| assert m * k is S.One | |
| assert m * W == W / 1000 | |
| assert k * k == M | |
| assert 1 / m == k | |
| assert k / m == M | |
| assert dodeca * dodeca == 144 | |
| assert 1 / dodeca == S.One / 12 | |
| assert k / dodeca == S(1000) / 12 | |
| assert dodeca / dodeca is S.One | |
| m = Quantity("fake_meter") | |
| SI.set_quantity_dimension(m, S.One) | |
| SI.set_quantity_scale_factor(m, S.One) | |
| assert dodeca * m == 12 * m | |
| assert dodeca / m == 12 / m | |
| expr1 = kilo * 3 | |
| assert isinstance(expr1, Mul) | |
| assert expr1.args == (3, kilo) | |
| expr2 = kilo * x | |
| assert isinstance(expr2, Mul) | |
| assert expr2.args == (x, kilo) | |
| expr3 = kilo / 3 | |
| assert isinstance(expr3, Mul) | |
| assert expr3.args == (Rational(1, 3), kilo) | |
| assert expr3.args == (S.One/3, kilo) | |
| expr4 = kilo / x | |
| assert isinstance(expr4, Mul) | |
| assert expr4.args == (1/x, kilo) | |
| def test_prefix_unit(): | |
| m = Quantity("fake_meter", abbrev="m") | |
| m.set_global_relative_scale_factor(1, meter) | |
| pref = {"m": PREFIXES["m"], "c": PREFIXES["c"], "d": PREFIXES["d"]} | |
| q1 = Quantity("millifake_meter", abbrev="mm") | |
| q2 = Quantity("centifake_meter", abbrev="cm") | |
| q3 = Quantity("decifake_meter", abbrev="dm") | |
| SI.set_quantity_dimension(q1, length) | |
| SI.set_quantity_scale_factor(q1, PREFIXES["m"]) | |
| SI.set_quantity_scale_factor(q1, PREFIXES["c"]) | |
| SI.set_quantity_scale_factor(q1, PREFIXES["d"]) | |
| res = [q1, q2, q3] | |
| prefs = prefix_unit(m, pref) | |
| assert set(prefs) == set(res) | |
| assert {v.abbrev for v in prefs} == set(symbols("mm,cm,dm")) | |
| def test_bases(): | |
| assert kilo.base == 10 | |
| assert kibi.base == 2 | |
| def test_repr(): | |
| assert eval(repr(kilo)) == kilo | |
| assert eval(repr(kibi)) == kibi | |