How to select columns based on a known repeated pattern.

I have data that came from excel and I want to grab the data without all the comments. I have imported the data into matlab but now I am having trouble selecting it cleanly. If the data is in a variable called raw I do the following.

data = raw(:,28:22:end);
data = [data, raw(:,29:22:end)];
data = [data, raw(:,30:22:end)];
data = [data, raw(:,31:22:end)];
data = [data, rwa(:,32:22:end)];

The problem with this is I have to reorder everything afterwards to get the columns back in the right order. I want to select all the columns like:

data = raw(:,[28:32]:22:end);

or something similiar. I figure there must be some ultra fancy vector way of doing this in 1 shot.

Answer 1

[Andrei Bobrov]

data = raw(:,bsxfun(@plus,29:32,22*(0:floor((size(raw,2)-32)/22))'));

Answer 2

[the cyclist]

One marginally better possibility:

data = raw(:, [28:22:end 29:22:end 30:22:end 31:22:end 32:22:end]);

Answer 3

[Kelly Kearney]

Not quite one shot, but a little less typing:

n = size(raw, 2);
idx = bsxfun(@plus, (1:22:n)', 28:32);
idx = idx(idx <= n);

data = raw(:,idx);

[Matt]

2 minor things but this is good.

idx = bsxfun(@plus, (1:22:n)', 27:31);
idx = sort(idx(idx <= n)); % sorts the columns in the right order