def do_draw(self, data):
def draw_float_bytes(random, n):
assert n == 8
while True:
i = random.randint(1, 10)
if i <= 4:
f = random.choice(NASTY_FLOATS)
elif i == 5:
return bytes_from_list(
random.randint(0, 255) for _ in range(8))
elif i == 6:
f = random.random() * (random.randint(0, 1) * 2 - 1)
elif i == 7:
f = random.gauss(0, 1)
elif i == 8:
f = float(random.randint(-2**63, 2**63))
else:
f = random.gauss(random.randint(-2**63, 2**63), 1)
if self.permitted(f):
return struct_pack(b'!d', f)
result = struct_unpack(b'!d',
hbytes(data.draw_bytes(8, draw_float_bytes)))[0]
assume(self.permitted(result))
return result
def next_up(value):
"""Return the first float larger than finite `val` - IEEE 754's `nextUp`.
From https://stackoverflow.com/a/10426033, with thanks to Mark Dickinson.
"""
assert isinstance(value, float)
if math.isnan(value) or (math.isinf(value) and value > 0):
return value
if value == 0.0:
value = 0.0
# Note: n is signed; float_to_int returns unsigned
n = struct_unpack(b'q', struct_pack(b'd', value))[0]
if n >= 0:
n += 1
else:
n -= 1
return struct_unpack(b'd', struct_pack(b'q', n))[0]
def reinterpret_bits(x, from_, to):
if from_ == b"!e":
arr = numpy.array([x], dtype=">f2")
if numpy.isfinite(x) and not numpy.isfinite(arr[0]):
quiet_raise(OverflowError("%r too large for float16" % (x, )))
buf = arr.tobytes()
else:
buf = struct_pack(from_, x)
if to == b"!e":
return float(numpy.frombuffer(buf, dtype=">f2")[0])
return struct_unpack(to, buf)[0]
def reinterpret_bits(x, from_, to):
if from_ == b'!e':
arr = numpy.array([x], dtype='>f2')
if numpy.isfinite(x) and not numpy.isfinite(arr[0]):
quiet_raise(OverflowError('%r too large for float16' % (x,)))
buf = arr.tobytes()
else:
buf = struct_pack(from_, x)
if to == b'!e':
return float(numpy.frombuffer(buf, dtype='>f2')[0])
return struct_unpack(to, buf)[0]
def do_draw(self, data):
while True:
data.start_example()
i = self.sampler.sample(data)
if i == 0:
result = struct_unpack(b'!d', hbytes(data.draw_bytes(8)))[0]
else:
result = self.nasty_floats[i - 1]
data.write(struct_pack(b'!d', result))
data.stop_example()
if self.permitted(result):
return result
def do_draw(self, data):
def draw_float_bytes(random, n):
assert n == 8
i = random.randint(0, 20)
if i <= 2:
f = random.choice(self.critical)
else:
f = random.random() * (self.upper_bound -
self.lower_bound) + self.lower_bound
return struct_pack(b'!d', f)
f = struct_unpack(b'!d', hbytes(data.draw_bytes(8,
draw_float_bytes)))[0]
assume(self.lower_bound <= f <= self.upper_bound)
assume(sign(self.lower_bound) <= sign(f) <= sign(self.upper_bound))
return f
def reinterpret_bits(x, from_, to):
return struct_unpack(to, struct_pack(from_, x))[0]
def reinterpret_bits(x, from_, to):
return struct_unpack(to, struct_pack(from_, x))[0]
def int_to_float(value):
return struct_unpack(b'!d', struct_pack(b'!Q', value))[0]
def float_to_int(value):
return (struct_unpack(b'!Q', struct_pack(b'!d', value))[0])