function prob = mixture(mix, x)
%計算輸出概率
%輸入:
%  mix  -- 混合高斯結構
%  x    -- 輸入向量, SIZE*1
%輸出:
%  prob -- 輸出概率

prob = 0;
for j = 1:mix.M
	m = mix.mean(j,:);
	v = mix.var (j,:);
	w = mix.weight(j);
	prob = prob + w * pdf(m, v, x);
end

% 加上realmin, 以防止viterbi.m中計算log(prob)時溢出
if prob==0, prob=realmin; end