# Never mind the details of this function...
def pretty_print_fp(x):
print("---------------------------------------------")
print("Floating point structure for %r" % x)
print("---------------------------------------------")
import struct
s = struct.pack("d", x)
def get_bit(i):
byte_nr, bit_nr = divmod(i, 8)
return int(bool(
s[byte_nr] & (1 << bit_nr)
))
def get_bits(lsb, count):
return sum(get_bit(i+lsb)*2**i for i in range(count))
# https://en.wikipedia.org/wiki/Double_precision_floating-point_format
print("Sign bit (1:negative):", get_bit(63))
stored_exponent = get_bits(52, 11)
fraction = get_bits(0, 52)
if stored_exponent == 0:
exponent = -1022
significand = fraction
else:
exponent = stored_exponent - 1023
significand = fraction + 2**52
print("Stored exponent value: %d" % stored_exponent)
print("Mathematical exponent: %d" % exponent)
print("Fraction (bin): {0:052b}".format(fraction))
print("Signif. (bin): {0:053b}".format(significand))
print("Significand (decimal, scaled to <=2):", repr(significand / (2**52)))
pretty_print_fp(1)
Things to try:
float("nan")