帮我写一个MATLAB代码进行仿真题目如下：实现算术编码和译码，要完整代码

以下是MATLAB中实现算术编码和译码的完整代码：

%% 算术编码和译码

% 编码函数
function [code, prob] = arithmetic_encode(source, prob)

% 确定源符号总数和编码区间
num_symbols = length(prob);
low = zeros(num_symbols, 1);
high = zeros(num_symbols, 1);
for i = 1:num_symbols
    if i == 1
        low(i) = 0;
        high(i) = prob(i);
    else
        low(i) = high(i-1);
        high(i) = low(i) + prob(i);
    end
end

% 初始化编码区间和缓存
range = high(num_symbols);
code = 0;
buffer = 0;
buffer_bits = 0;

% 编码每个符号
for i = 1:length(source)
    % 获取当前符号的编码区间
    symbol = source(i);
    symbol_low = low(symbol);
    symbol_high = high(symbol);
    
    % 更新编码区间和缓存
    range = range * (symbol_high - symbol_low);
    code = code * (symbol_high - symbol_low) + symbol_low;
    while range < 0.5
        % 输出当前缓存位的1或0
        if buffer >= 0.5
            code = code * 2 - 1;
        else
            code = code * 2;
        end
        buffer = 2 * (buffer - floor(buffer));
        buffer_bits = buffer_bits + 1;
        range = 2 * range;
    end
end

% 输出缓存中的剩余位
if buffer >= 0.5
    code = code * 2 - 1;
else
    code = code * 2;
end
while buffer_bits > 0
    code = code * 2;
    buffer_bits = buffer_bits - 1;
end

% 输出概率表
prob = prob(:)';

end

% 译码函数
function source = arithmetic_decode(code, prob, num_symbols)

% 确定编码区间和缓存
range = 1;
buffer = 0;
buffer_bits = 0;

% 初始化源符号序列
source = zeros(num_symbols, 1);

% 译码每个符号
for i = 1:num_symbols
    % 获取当前符号的编码区间
    prob_cum = [0; cumsum(prob)];
    symbol = find(code/range >= prob_cum, 1, 'last');
    symbol_low = prob_cum(symbol);
    symbol_high = prob_cum(symbol+1);
    
    % 更新编码区间和缓存
    range = range * (symbol_high - symbol_low);
    code = code * (symbol_high - symbol_low) - symbol_low;
    while range < 0.5
        % 读入一位缓存
        buffer = 2 * buffer + (code >= 0.5);
        code = 2 * code;
        buffer_bits = buffer_bits + 1;
        range = 2 * range;
    end
    
    % 输出当前符号
    source(i) = symbol;
end

end

% 测试算术编码和译码
prob = [0.1, 0.15, 0.2, 0.3, 0.25];
source = [3, 2, 4, 1, 5];
[code, prob_out] = arithmetic_encode(source, prob);
source_out = arithmetic_decode(code, prob_out, length(source));
disp(['源符号序列：', num2str(source)]);
disp(['编码后的二进制：', dec2bin(round(code*2^20))]);
disp(['译码后的源符号序列：', num2str(source_out)]);

其中，`arithmetic_encode`函数用于对给定的源符号序列进行算术编码，返回编码后的二进制序列和概率表；`arithmetic_decode`函数用于对给定的编码后的二进制序列和概率表进行算术译码，返回译码后的源符号序列。最后一个段落是一个测试例子，展示了算术编码和译码的完整流程。