p2_q6.py

# -*- coding: utf-8 -*-
"""p2_q6.ipynb

Automatically generated by Colaboratory.

Original file is located at
    https://colab.research.google.com/drive/1OIsDsX2UwGbqDEG21pfBe-gvsHnvdFXi
"""

""" Q6. The expected length is sum p_i *l_i, probability of a symbol multiplied by the length of the encoding"""
# Calculate the probabilities of the symbols : take the frequencies and divide it by the number of simbols
f = len(genome)/3
for key, value in codons_cnt.items():
    codons_cnt[key] = value/f          # The sum of the new codons_cnt.values() gives 1. 
# From code_map.values() we can take the length of the encoded symbol

array = []
for value in code_map.values():
  array.append(value)
array1 = []
for value in codons_cnt.values():
  array1.append(value)

length = np.array(array)
print(length)
prob = np.array(array1)
print(prob)
prob = prob.astype(np.float)
length = length.astype(np.float)

# Expected length
final = np.dot(prob, length)

#total length of the encoded text divided by the number of encoded symbols,
empirical = len(compressed)/len(length)
print(empirical)

entropy = - np.sum(prob*np.log(prob))
print(entropy)