我使用 Matlab 生成了马尔可夫链。从生成的马尔可夫链中,我需要计算概率密度函数 (PDF)。
- 我该怎么做?
我应该在任何 PDF 函数中直接使用生成的马尔可夫链吗?
或者
我应该在找到 PDF 之前对数据进行任何预处理吗?
使用以下代码生成马尔可夫链:
% x = the quantity corresponding to each state, typical element x(i)
% P = Markov transition matrix, typical element p(i,j) i,j=1,...n
% pi0 = probability distribution over initial state
% T = number of periods to simulate
% chain = sequence of realizations from the simulation
n = length(x); % what is the size of the state vector?
E = rand(1,T); % T-vector of draws from independent uniform [0,1]
cumsumP = P*triu(ones(size(P)));
E0 = rand(1,1);
ppi0 = [0,cumsum(pi0)];
s0 = ((E0<=ppi0(2:n+1)).*(E0>ppi0(1:n)))';
s = s0;
for t=1:T,
state(:,t) = s;
ppi = [0,s'*cumsumP];
s = ((E(t)<=ppi(2:n+1)).*(E(t)>ppi(1:n)))';
end
chain = x'*state;
生成马尔可夫链后,我需要计算概率密度。
- 如何使用 Matlab 找到概率密度?