How can I add element in cell array?

I have a cell array

A = {[2 3 4 ];
[5 6 7 8];
[9 10 11]}

I want add element "1" in start of every array of the cell after adding some constant to every element of "A". e.g.

% B = {1 1+A}

How can I do this on matlab without destructring my cell A.

Answer 1

[TADA]

This sort of operations is best performed on matrices and not cell arrays

So it's better to transform your cell array into a matrix first. you can resize your arrays filling them with NaN to fit the longest arrays using padarray if you have image processing toolbox:

A = {[2 3 4 ];...
     [5 6 7 8];...
     [9 10 11]};
 
% find length of longest vector 
maxLength = max(cellfun(@length, A));

% pad all vectors with NaN to fit this length
A = cellfun(@(a) padarray(a, [0, maxLength - length(a)], nan, 'post'), A, 'UniformOutput', false);

% turn into matrix and perform operations
B = [ones(size(A,1),1), cell2mat(A) + 1]

B =

     1     3     4     5   NaN
     1     6     7     8     9
     1    10    11    12   NaN
     

If you MUST use a cell array at some point for some reason, you can always change it back to a cell array:

% turn back to cell array
A = mat2cell(B, repmat(size(A,2),1,size(A,1)));

% get rid of NaN values
A = cellfun(@(a) a(~isnan(a)), A, 'UniformOutput', false);

% show cell contents
celldisp(A);

A{1} =
 
     1     3     4     5

 
 
A{2} =
 
     1     6     7     8     9

 
 
A{3} =
 
     1    10    11    12
     

But if you MUST use a cell array, you are better off with an old school for loop:

A = {[2 3 4 ];...
     [5 6 7 8];...
     [9 10 11]};
 
for i = 1:length(A)
    A{i} = [1, A{i} + 1];
end

% show cell contents
celldisp(A);

A{1} =
 
     1     3     4     5

 
 
A{2} =
 
     1     6     7     8     9

 
 
A{3} =
 
     1    10    11    12