通过MATLAB的程序解决相应图上处理中熵值和概率的问题-Adaptive Arithmetic coding. A source generates symbols from alphabet {A, B, C, D}.

Probabilities of occurrence of the symbols are initially estimated as: Pr(A)=Pr(B)=0.25,

Pr(C)= 0.2, and Pr(D)=0.3. After 100 generated symbols, the statistics changes to Pr(A)=

0.1, Pr(B)=0.3, Pr(C)= 0.4, and Pr(D)=0.2. After 300 symbols, statistics is: Pr(A)=0.6,

Pr(B)=0.05　Pr(C)=0.1, and Pr(D)=0.25.

Randomly generate a source sequence of length 500 symbols drawing the

symbols from the true source distributions. That is, for the first 100 symbols, next

300 symbols, and last 100 symbols use the three distributions above,

respectively. Encode this sequence using adaptive arithmetic coding that

adaptively changes frequency of the source symbol occurrence every 100

symbols. Decode the sequence and compare the decoded and original sequences.

Find the efficiency of the code.