I am writing code that will have negative and positive numbers all 16 bits long with the MSB being the sign aka two's complement. This means the smallest number I can have is -32768 which is 1000 0000 0000 0000
in two's complement form. The largest number I can have is 32767 which is 0111 1111 1111 1111
.
The issue I am having is python is representing the negative numbers with the same binary notation as positive numbers just putting a minus sign out the front i.e. -16384 is displayed as -0100 0000 0000 0000
what I want to be displayed for a number like -16384 is 1100 0000 0000 0000
.
I am not quite sure how this can be coded. This is the code i have. Essentially if the number is between 180 and 359 its going to be negative. I need to display this as a twos compliment value. I dont have any code on how to display it because i really have no idea how to do it.
def calculatebearingActive(i):
numTracks = trackQty_Active
bearing = (((i)*360.0)/numTracks)
if 0< bearing <=179:
FC = (bearing/360.0)
FC_scaled = FC/(2**(-16))
return int(FC_scaled)
elif 180<= bearing <=359:
FC = -1*(360-bearing)/(360.0)
FC_scaled = FC/(2**(-16))
return int(FC_scaled)
elif bearing ==360:
FC = 0
return FC
If you're doing something like
format(num, '016b')
to convert your numbers to a two's complement string representation, you'll want to actually take the two's complement of a negative number before stringifying it:
format(num if num >= 0 else (1 << 16) + num, '016b')
or take it mod 65536
:
format(num % (1 << 16), '016b')