Question

挣扎着几行编码。

这是上下文：考虑一个公平的硬币被扔1000次并让X成为的实验三个连续头部的模式出现的次数。注意允许重叠，因此如果序列是HHHHTT···TT，那么X = 2。估计 X的概率质量函数并用它来估计 X的均值和方差。报告您的（时刻）估计值。

这是提供的模板，并突出显示了我需要添加的5行代码及其说明。

clear all

N=1000; %Number of Die Rolls
nreps=10000;
count=zeros(1,N+1); %count will be a vector of size N+1 such that, for i=0...N, c(i+1)/nreps=P(X=i)     

for n=1:nreps
     n_3H = 0; %count the number of occurrences of the pattern HHH
        ***%Add code to toss a coin N times***
      for i=3:N
        if  ***%Add condition that the pattern HHH appears at position (i-2,i-1,i)***
            n_3H = n_3H+1;
        end
      end
     ***%Add code to increment count(n_3H+1) by 1***
end

RelFreq = count/nreps;

meanX  ***%Add code to estimate the mean of X***
varX  ***%Add code to estimate the variance of X***

到目前为止，这就是我所拥有的，但它似乎没有返回任何东西，我不确定我应该做些什么来继续。

clear all

 N=1000; %Number of Die Rolls
nreps=100;
count=zeros(1,N+1);%count will be a vector of size N+1 such that, for i=0...N, c(i+1)/nreps=P(X=i)     

for n=1:nreps
     n_3H = 0; %count the number of occurrences of the pattern HHH
      flipStates = randi([1, 2], 1, N)  %Add code to toss a coin N times
      for i=3:N
        if  strfind(flipStates, [1,1,1])%Add condition that the pattern HHH appears at position (i-2,i-1,i)
            n_3H = n_3H+1;
        end
      end
      %Add code to increment count(n_3H+1) by 1
end

RelFreq = count/nreps;

meanX  %Add code to estimate the mean of X
varX  %Add code to estimate the variance of X

任何帮助将不胜感激！

Answer 1

因为在整个抛掷序列中循环并分别检查每个子序列，你应该这样做：

if all(flipStates(i-2:i) == [1,1,1])

你所做的是检查MATLAB翻译为if的向量的if all(vector)条件。

如果你把它取出（实际上是代替）循环，你的方法是正确的：for i=3:N ...并执行：n_3H = numel(strfind(flipStates,[1 1 1]))

无法找到正确的代码行来确定MATLAB中的分布

1 个答案: