mk_ghmm_obs_lik.m

隐马尔科夫模型对文本信息进行抽取利用MATLAB实现

function B = mk_ghmm_obs_mat(data, mu, Sigma)
% MK_GHMM_OBS_MAT Make the sequence-specific observation matrix for a Gaussian-output HMM.
% B = mk_ghmm_obs_mat(data, mu, Sigma)
%
% Inputs:
% data(:,t) = y(t) = observation vector at time t
% mu(:,j) = E[Y(t) | Q(t)=j]
% Sigma(:,:,j) = Cov[Y(t) | Q(t)=j]
%
% Output:
% B(i,t) = Pr(y(t) | Q(t)=i)

Q = size(mu, 2);
O = size(data, 1);
T = size(data, 2);
B = zeros(Q,T);

for j=1:Q
  B(j,:) = gaussian_prob(data, mu(:,j), Sigma(:,:,j))';
end