Reshape a cell avoiding the loop

I have the cell for example:

a = 

      '0.0'    '0.0' 
      '0.1'    '-0.4'
      '0.1'    '0.8' 
      '0.2'    '2.3' 
      '0.3'    '3.4' 
      '0.3'    '-3.2'
      '0.4'    '-6.9'
      '0.5'    '-1.8'
      '0.5'    '7.2' 
      '0.6'    '10.0'

and I want o reshape it like this.

d = 

      '0.0'    '0.0'     '0.3'    '-3.2'
      '0.1'    '-0.4'    '0.4'    '-6.9'
      '0.1'    '0.8'     '0.5'    '-1.8'
      '0.2'    '2.3'     '0.5'    '7.2' 
      '0.3'    '3.4'     '0.6'    '10.0'

I want to avoid the loop because the cell dimensions are very large. Thank you!

Answer 1

[Iain]

I think:

 b = a';
 c = reshape(b,cols,rows,numel(a)/cols/rows);
 c = permute(c,[2 1 3]);
 d = reshape(c,[],rows);

should do it...

[Giorgos Papakonstantinou]

numel(a)/cols/rows will always be equal to 1.

cols and rows variables refer to b?

[Iain]

cols, is the number of columns in a, rows is the number of rows you want to segment by, so your updated example would have them both being two, and the third one dimension would be 5

[Giorgos Papakonstantinou]

So like this:

 b = a';

 c = reshape(b,2,2,numel(a)/2/2);

 c = permute(c,[2 1 3]);
 d = reshape(c,[],2);

[Giorgos Papakonstantinou]

but i get this:

d = 

    '0.0'     '3.4' 
    '0.1'     '-3.2'
    '0.0'     '0.4' 
    '-0.4'    '0.5' 
    '0.1'     '-6.9'
    '0.2'     '-1.8'
    '0.8'     '0.5' 
    '2.3'     '0.6' 
    '0.3'     '7.2' 
    '0.3'     '10.0'

[Giorgos Papakonstantinou]

I think by accident you made a typo.

It should be:

reshape(c,2,[])

Thank you. I really don't understand how permute works.

[Iain]

Permute swaps dimensions round.

Answer 2

[the cyclist]

d = [a(1:5,:),a(6:10,:)];

You can generalize this, of course, but you did not provide enough detail. If you always want the top half and bottom half, for example, you could use the size() command to determine the "height", and use half the height to determine the cutoff, which I just hard-coded as 5 here.

[Giorgos Papakonstantinou]

What if the the initial cell a has 100 rows and two columns (size 100x2). How do I cut the cell in sets of 5 avoiding the for loop. The resulting cell will have size 5x40 and it will start just as the cell d that I indicated above.

Answer 3

[Giorgos Papakonstantinou]

I am sorry I should be more explanatory. Let's say that I want to split in sets of 2 and concatenate them.

so it would be:

c =

    '0.0'    '0.0'     '0.1'    '0.8'    '0.3'    '3.4'     '0.4'    '-6.9'    '0.5'    '7.2' 
    '0.1'    '-0.4'    '0.2'    '2.3'    '0.3'    '-3.2'    '0.5'    '-1.8'    '0.6'    '10.0'