How to change array format - change row number and column number, but have all the data as before

Hi everyone,

I am interested in following if I put as an example;

I have an array A;

1 1 1 1
1 1 1 1
1 1 1 1
2 2 2 2
2 2 2 2
2 2 2 2
3 3 3 3
3 3 3 3
3 3 3 3

Now I would like to change this to array B which would look like;

1 1 1 1 2 2 2 2 3 3 3 3
1 1 1 1 2 2 2 2 3 3 3 3
1 1 1 1 2 2 2 2 3 3 3 3

How can I do this type of thing on matlab? The array A can have much more sets of data, and the code must go through each row of A until there is no more data.

Thanks a lot in advance! Sara

Answer 1

[Stephen23]

Depending on the required element order, (along 2nd dim first):

B = reshape(A.',3,[])

or (along 1st dim first):

B = reshape(permute(reshape(A,3,[],4),[1,3,2]),3,[])

or (along 1st dim first):

cell2mat(mat2cell(A,[3,3,3],4).')

[SNT]

Hi Stephen,

The first one doesn't quite give me the format I am looking for

when I input A ;

0.547008892  0.744692807  0.686775433
0.296320806  0.188955015  0.183511156
0.368484596  0.780227435  0.929385971
0.625618561  0.081125769  0.775712679
0.486791632  0.446783749  0.508508655
0.435858589  0.306349472  0.510771564
0.817627708  0.64431813  0.811580458
0.794831417  0.378609383  0.532825589
0.350727104  0.875942811  0.622475086
0.939001562  0.550156343  0.587044705

I get B as;

0.547008892  0.296320806  0.368484596  0.625618561  0.486791632  0.435858589  0.817627708  0.794831417  0.350727104  0.939001562
0.744692807  0.188955015  0.780227435  0.081125769  0.446783749  0.306349472  0.64431813  0.378609383  0.875942811  0.550156343
0.686775433  0.183511156  0.929385971  0.775712679  0.508508655  0.510771564  0.811580458  0.532825589  0.622475086  0.587044705

when I should be getting;

0.547008892  0.744692807  0.686775433  0.368484596  0.780227435  0.929385971  0.486791632  0.446783749  0.508508655  0.817627708  0.64431813  0.811580458  0.350727104  0.875942811  0.622475086
0.296320806  0.188955015  0.183511156  0.625618561  0.081125769  0.775712679  0.435858589  0.306349472  0.510771564  0.794831417  0.378609383  0.532825589  0.939001562  0.550156343  0.587044705

How can I modify the code to get the desired output? The again the number of data in the A can vary, and I must be able to specify at which rows to break and start a new column.. In this example, I have taken every two rows and placed them as a set of new columns.

Would be great if you could help me out!

Thanks!

[SNT]

Hi Stephen, also I get an error with the 3rd option;

C = cell2mat(mat2cell(A,[3,3,3],4).');
Error using mat2cell (line 97)
Input arguments, D1 through D2, must sum to each dimension of the input matrix
size, [15   4].'

How can I get the output I have stated in my comment above?

Thanks a lot!

Sara

[Stephen23]

>> reshape(permute(reshape(A.',size(A,2),2,[]),[2,1,3]),2,[])
ans =
  0.547009   0.744693   0.686775   0.368485   0.780227   0.929386   0.486792   0.446784   0.508509   0.817628   0.644318   0.811580   0.350727   0.875943   0.622475
  0.296321   0.188955   0.183511   0.625619   0.081126   0.775713   0.435859   0.306349   0.510772   0.794831   0.378609   0.532826   0.939002   0.550156   0.587045

[SNT]

Hi Stephen,

The second option

B = reshape(permute(reshape(A,3,[],4),[1,3,2]),3,[])

Seems to work great! Thanks