多列的randperm

Question

上一个问题Sampling在最后一行代码中给出的样本答案只返回1000x1而不是1000x6？

%% 
normIdx = strmatch('normal.', Book2);
normalSubset = fulldata(normIdx, :);
normal = randperm(size(normalSubset , 1));
p = normal(1:750)-1;

%
smurfIdx = strmatch('smurf.', Book2);
smurfSubset = fulldata(smurfIdx, :);
smurf = randperm(size(smurfSubset , 1));
a = smurf(1:250)-1;

%
normalSample = normalSubset (p, :);
smurfSample = smurfSubset (a, :);

%
sample = [normalSample ; smurfSubset]

%
sample = sample(randperm(1000)); % this line

我试过了：

sample = randperm( size(sample, 1));

这一行输出28,000条记录，显然不是我想要的。然后我尝试了：

rows = 1000;
columns = 6;

%# pick random columns
 indY = randperm( size(sample,2) );
 indY = indY(1:columns);

%# pick random rows
indX = randperm( size(sample,1) );
indX = indX(1:rows)';

%# filter data
sample = [indX ; indY];

但我无法连接最后一行？这只是试图修复1000x6问题的尝试，如果有人能想出一个更好的方式“一种工作方式”。

Answer 1

怎么样

 sample = sample(randperm(1000),:);