CODEWITHSUNDEEP
matlab
DimChtz
DimChtz

Reputation: 4333

Matlab - Getting submatrix

Okay, I use the following code to shuffle the rows of a MxN matrix called data:

newData = data(randperm(size(data, 1)), :);

So far so good, what I need now is to keep the first K rows. Of course I can do this:

newData = data(randperm(size(data, 1)), :);
newData = newData(1:K, :);

But I am trying to do this (just out of curiosity) in just one line. What I tried is this:

newData = data(randperm(size(data, 1)), :)(1:K, :);

Well, it obviously failed. I know it's not important and probably a stupid question but does anyone know a way to do this in one line?

Upvotes: 0

Views: 29

Answers (1)

craigim
craigim

Reputation: 3914

You're randomly permuting your matrix, then taking the top K rows. Instead, just select K random rows:

newData = data(randperm(size(data, 1), K), :);

The second argument to randperm says to choose K values from 1:size(data, 1).

Upvotes: 1

Related Questions