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Mini Shell
Mini Shell
from itertools import product
from sympy import symbols, exp, log, S
from sympy.codegen.numpy_nodes import logaddexp, logaddexp2
x, y, z = symbols('x y z')
def test_logaddexp():
lae_xy = logaddexp(x, y)
ref_xy = log(exp(x) + exp(y))
for wrt, deriv_order in product([x, y, z], range(0, 3)):
assert (
lae_xy.diff(wrt, deriv_order) -
ref_xy.diff(wrt, deriv_order)
).rewrite(log).simplify() == 0
one_third_e = 1*exp(1)/3
two_thirds_e = 2*exp(1)/3
logThirdE = log(one_third_e)
logTwoThirdsE = log(two_thirds_e)
lae_sum_to_e = logaddexp(logThirdE, logTwoThirdsE)
assert lae_sum_to_e.rewrite(log) == 1
assert lae_sum_to_e.simplify() == 1
assert logaddexp(2, 3).simplify() == logaddexp(2, 3) # cannot simplify with 2, 3
def test_logaddexp2():
lae2_xy = logaddexp2(x, y)
ref2_xy = log(2**x + 2**y)/log(2)
for wrt, deriv_order in product([x, y, z], range(0, 3)):
assert (
lae2_xy.diff(wrt, deriv_order) -
ref2_xy.diff(wrt, deriv_order)
).rewrite(log).simplify() == 0
def lb(x):
return log(x)/log(2)
two_thirds = S.One*2/3
four_thirds = 2*two_thirds
lbTwoThirds = lb(two_thirds)
lbFourThirds = lb(four_thirds)
lae2_sum_to_2 = logaddexp2(lbTwoThirds, lbFourThirds)
assert lae2_sum_to_2.rewrite(log) == 1
assert lae2_sum_to_2.simplify() == 1
assert logaddexp2(x, y).simplify() == logaddexp2(x, y) # cannot simplify with x, y
Zerion Mini Shell 1.0