Function File: arithmetic_encode (message, symbol_probabilites_list)

Computes the arithmetic code for the message with symbol probabilities are given. The arithmetic coding procedure assumes that message is a list of numbers and the symbol probabilities correspond to the index. For example

                   symbols=[1,2,3,4]; sym_prob=[0.5 0.25 0.15 0.10];
                   message=[1, 1, 2, 3, 4];
                   arithmetic_encode(message,sym_prob) ans=0.18078