def test_log2():
from rpython.rlib import rfloat
assert rfloat.log2(1.0) == 0.0
assert rfloat.log2(2.0) == 1.0
assert rfloat.log2(2.0**1023) == 1023.0
assert 1.584 < rfloat.log2(3.0) < 1.585
py.test.raises(ValueError, rfloat.log2, 0)
py.test.raises(ValueError, rfloat.log2, -1)
def test_log2():
from rpython.rlib import rfloat
assert rfloat.log2(1.0) == 0.0
assert rfloat.log2(2.0) == 1.0
assert rfloat.log2(2.0**1023) == 1023.0
assert 1.584 < rfloat.log2(3.0) < 1.585
py.test.raises(ValueError, rfloat.log2, 0)
py.test.raises(ValueError, rfloat.log2, -1)
def _log_any(space, w_x, base):
# base is supposed to be positive or 0.0, which means we use e
try:
try:
x = _get_double(space, w_x)
except OperationError as e:
if not e.match(space, space.w_OverflowError):
raise
if not space.isinstance_w(w_x, space.w_int):
raise
# special case to support log(extremely-large-long)
num = space.bigint_w(w_x)
result = num.log(base)
else:
if base == 10.0:
result = math.log10(x)
elif base == 2.0:
result = rfloat.log2(x)
else:
result = math.log(x)
if base != 0.0:
den = math.log(base)
result /= den
except OverflowError:
raise oefmt(space.w_OverflowError, "math range error")
except ValueError:
raise oefmt(space.w_ValueError, "math domain error")
return space.newfloat(result)