I have a cell array (36*72*1000), I wish to extract every other cell column-wise and every cell row-wise...

So,

I want to extract cell a2, b4, c6 etc from:

a1 a2 a3 a4;
b1 b2 b3 b4;

ie. I should have 36 values, which I would like displayed as a column for each of my 1000 matrices. So a new cell array 36*1*1000 - does this make sense?!

Can someone please show me how this can be done?

Thanks in advance...

Answer 1

[Sean de Wolski]

C(:,2:2:end,:) %all rows, even columns, all pages

More

Since you only want one element from each row, it will require a little extra work. Here is one approach:

C = num2cell(rand(4,8,5));  %sample cell
sz = size(C); %how big?
C2 = C(:,2:2:end,:); %remove every other column
idxEye = repmat(logical(eye(sz(1))),[1 1 sz(3)]); %create a logical 3d index of the diagonal
C3 = reshape(C2(idxEye),sz(1),1,sz(3)) %extract and reshape

[John]

Can you help me a little more please, how do i put this into a for loop to get the output i require? sorry if this is stupid...!

[Sean de Wolski]

You don't need a for-loop.

C2 = what_I_have_above;

will do the extraction for you!

[Sean de Wolski]

Actually that will only do the first part - see more.