??? Subscript indices must either be real positive integers or logicals.这是什么原因呢

disp('正在计算参考模板的参数...')
for i=1:10
    fname = sprintf('0.wav',i-1);
    x = wavread(fname);
    [x1,x2] = vad(x);
    m = mfcc(x);
    m = m(x1-2:x2-2,:);
    ref(i).mfcc = m;
end
disp('正在计算测试模板的参数...')
for i=1:10
    fname = sprintf('t0.wav',i-1);
    x = wavread(fname);
    [x1,x2] = vad(x);
    m = mfcc(x);
    m = m(x1-2:x2-2,:);
    test(i).mfcc = m;
end
disp('正在进行模板匹配...')
dist = zeros(10,10);
for i=1:10
for j=1:10
    dist(i,j) = dtw(test(i).mfcc, ref(j).mfcc);
end
end
disp('正在计算匹配结果...')
for i=1:10
    [d,j] = min(dist(i,:));
    fprintf('测试模板 %d 的识别结果为：%d\n', i, j);
end
正在计算参考模板的参数...
??? Subscript indices must either be real positive integers or logicals.