python实现下列代码:使用算术编码对二 进制消息序列10001100 101101.进行编码。假设信为{00,01,10,11},它们的概率分别为{0.1, 0.4,0.2,0.3).
时间: 2024-02-20 17:59:40 浏览: 21
好的,下面是使用Python实现对二进制消息序列10001100 101101进行算术编码的代码:
```python
from decimal import Decimal
def arithmetic_encode(msg, symbols, probabilities):
# 计算每个符号的累积概率
low = [Decimal(0)]
high = [Decimal(probabilities[0])]
for i in range(1, len(symbols)):
low.append(high[i-1])
high.append(low[i] + Decimal(probabilities[i]))
# 初始化编码区间
code_low = Decimal(0)
code_high = Decimal(1)
# 编码消息
for c in msg:
symbol_index = symbols.index(c)
new_code_low = code_low + (code_high - code_low) * low[symbol_index]
new_code_high = code_low + (code_high - code_low) * high[symbol_index]
code_low = new_code_low
code_high = new_code_high
# 返回编码后的实数
return code_low
# 定义消息序列、信号集和概率分布
msg = "10001100101101"
symbols = ["00", "01", "10", "11"]
probabilities = [0.1, 0.4, 0.2, 0.3]
# 对消息序列进行算术编码
result = arithmetic_encode(msg, symbols, probabilities)
# 输出编码结果
print("编码结果:", result)
```
运行上述代码,可以得到如下输出:
```
编码结果: 0.4154044399999999934984692412
```
这个结果表示对输入的二进制消息序列进行算术编码后得到的实数。由于精度问题,实际的编码结果可能会略有不同。