HBLink/hamming.py
2016-10-20 20:56:19 -05:00

62 lines
2.9 KiB
Python
Executable File

#!/usr/bin/env python
#
# This work is licensed under the Creative Attribution-NonCommercial-ShareAlike
# 3.0 Unported License.To view a copy of this license, visit
# http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to
# Creative Commons, 444 Castro Street, Suite 900, Mountain View,
# California, 94041, USA.
from __future__ import print_function
from bitarray import bitarray
# Does anybody read this stuff? There's a PEP somewhere that says I should do this.
__author__ = 'Cortney T. Buffington, N0MJS'
__copyright__ = 'Copyright (c) 2016 Cortney T. Buffington, N0MJS and the K0USY Group'
__credits__ = 'Jonathan Naylor, G4KLX'
__license__ = 'Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported'
__maintainer__ = 'Cort Buffington, N0MJS'
__email__ = 'n0mjs@me.com'
#------------------------------------------------------------------------------
# Hamming 15,11,3 routines
#------------------------------------------------------------------------------
# ENCODER- returns a bitarray object containing the hamming checksums
def enc_15113(_data):
csum = bitarray(4)
csum[0] = _data[0] ^ _data[1] ^ _data[2] ^ _data[3] ^ _data[5] ^ _data[7] ^ _data[8]
csum[1] = _data[1] ^ _data[2] ^ _data[3] ^ _data[4] ^ _data[6] ^ _data[8] ^ _data[9]
csum[2] = _data[2] ^ _data[3] ^ _data[4] ^ _data[5] ^ _data[7] ^ _data[9] ^ _data[10]
csum[3] = _data[0] ^ _data[1] ^ _data[2] ^ _data[4] ^ _data[6] ^ _data[7] ^ _data[10]
return csum
#------------------------------------------------------------------------------
# Hamming 13,9,3 routines
#------------------------------------------------------------------------------
# ENCODER - returns a bitarray object containing the hamming checksums
def enc_1393(_data):
csum = bitarray(4)
csum[0] = _data[0] ^ _data[1] ^ _data[3] ^ _data[5] ^ _data[6]
csum[1] = _data[0] ^ _data[1] ^ _data[2] ^ _data[4] ^ _data[6] ^ _data[7]
csum[2] = _data[0] ^ _data[1] ^ _data[2] ^ _data[3] ^ _data[5] ^ _data[7] ^ _data[8]
csum[3] = _data[0] ^ _data[2] ^ _data[4] ^ _data[5] ^ _data[8]
return csum
#------------------------------------------------------------------------------
# Hamming 16,11,4 routines
#------------------------------------------------------------------------------
# ENCODER - returns a bitarray object containing the hamming checksums
def enc_16114(_data):
assert len(_data) == 11, 'Hamming Encoder 16,11,4: Data not 11 bits long'
csum = bitarray(5)
csum[0] = _data[0] ^ _data[1] ^ _data[2] ^ _data[3] ^ _data[5] ^ _data[7] ^ _data[8]
csum[1] = _data[1] ^ _data[2] ^ _data[3] ^ _data[4] ^ _data[6] ^ _data[8] ^ _data[9]
csum[2] = _data[2] ^ _data[3] ^ _data[4] ^ _data[5] ^ _data[7] ^ _data[9] ^ _data[10]
csum[3] = _data[0] ^ _data[1] ^ _data[2] ^ _data[4] ^ _data[6] ^ _data[7] ^ _data[10]
csum[4] = _data[0] ^ _data[2] ^ _data[5] ^ _data[6] ^ _data[8] ^ _data[9] ^ _data[10]
return csum