Parity check always fails when the first bit is changed #1

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1. danielmuthama commented on Dec 1, 2020

   

   danielmuthama

   on Dec 1, 2020

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   Responding to issue #1. Thanks emilio-nuno for sharing the issue with me. Let me look into it and I will get back to you sooner. Will it be possible to share your module please
2. emilio-nuno commented on Dec 1, 2020

   

   emilio-nuno

   on Dec 1, 2020

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   def generar(d):
       data = list(d)
       data.reverse()
       c, ch, j, r, h = 0, 0, 0, 0, []
   
       while ((len(d) + r + 1) > (pow(2, r))):
           r = r + 1
   
       for i in range(0, (r + len(data))):
           p = (2 ** c)
   
           if (p == (i + 1)):
               h.append(0)
               c = c + 1
   
           else:
               h.append(int(data[j]))
               j = j + 1
   
       for parity in range(0, (len(h))):
           ph = (2 ** ch)
           if (ph == (parity + 1)):
               startIndex = ph - 1
               i = startIndex
               toXor = []
   
               while (i < len(h)):
                   block = h[i:i + ph]
                   toXor.extend(block)
                   i += 2 * ph
   
               for z in range(1, len(toXor)):
                   h[startIndex] = h[startIndex] ^ toXor[z]
               ch += 1
   
       h.reverse()
       return ''.join(map(str, h))
   
   def detectar_error_externo(d):
       data = list(d)
       data.reverse()
       c, ch, j, r, error, h, parity_list, h_copy = 0, 0, 0, 0, 0, [], [], []
   
       for k in range(0, len(data)):
           p = (2 ** c)
           h.append(int(data[k]))
           h_copy.append(data[k])
           if (p == (k + 1)):
               c = c + 1
   
       for parity in range(0, (len(h))):
           ph = (2 ** ch)
           if (ph == (parity + 1)):
   
               startIndex = ph - 1
               i = startIndex
               toXor = []
   
               while (i < len(h)):
                   block = h[i:i + ph]
                   toXor.extend(block)
                   i += 2 * ph
   
               for z in range(1, len(toXor)):
                   h[startIndex] = h[startIndex] ^ toXor[z]
               parity_list.append(h[parity])
               ch += 1
       parity_list.reverse()
       error = sum(int(parity_list) * (2 ** i) for i, parity_list in enumerate(parity_list[::-1]))
   
       if ((error) == 0):
           #print('There is no error in the hamming code received')
           return -1
   
       elif ((error) >= len(h_copy)):
           #print('Error cannot be detected')
           pass
   
       else:
           return error
           #print('Error is in', error, 'bit')
   
           if (h_copy[error - 1] == '0'):
               h_copy[error - 1] = '1'
   
           elif (h_copy[error - 1] == '1'):
               h_copy[error - 1] = '0'
               print('After correction hamming code is:- ')
           h_copy.reverse()
           print(int(''.join(map(str, h_copy))))
   
   if __name__ == '__main__':
       detectar_error_externo('01110')
   
   
3. danielmuthama commented on Dec 2, 2020

   

   danielmuthama

   on Dec 2, 2020

   Owner

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   Responding to issue #1. Emilio-nuno, I have your point now, I will have to schedule some time tomorrow for thorough debugging and validation but you can also find time and help in resolving the matter