How to unnest nested cell arrays??

Dear all,

I have nested cell array as shown in the attached picture. I wanted to convert it into a Matrix but that doesn't work so easily using cell2mat. So I thought I could try to make them all the same size then I could open them up with cell2mat. To open them up I would take the length of my maximum array and add zeros to the rest of my arrays to have them the same size. I used this to do that:

maxLength = max(cellfun(@numel,A));  % A is the name of my cell array
out=(cellfun(@(x)cat(2,x,zeros(1,maxLength-length(x))),A,'UniformOutput',false)); %Filling the cells with zeros

But I don't get extra cells with zeros, instead I am getting one cell that is holding all the zeros, I have attached a picture of my result.

So my question is, what am I doing wrong? Or is there a different approach of turning my nested cell arrays into a matrix??

Thank You

[Cedric]

I would be easier if you attached a MAT-File instead of pictures.

Answer 1

[Cedric]

It is a very good attempt. Here is an example that is almost what you did:

 >> A = {{5,6}; {7}; {8,9,3}}
 A =
  3×1 cell array
    {1×2 cell}
    {1×1 cell}
    {1×3 cell}

 >> maxLength = max(cellfun(@numel,A));
 >> result = cellfun( @(x) [cell2mat(x), zeros(1,maxLength-numel(x))], A, 'UniformOutput', false )
 result =
  3×1 cell array
    {1×3 double}
    {1×3 double}
    {1×3 double}

 >> result = vertcat( result{:} )
 result =
     5     6     0
     7     0     0
     8     9     3

You chose the other option to concatenate zeros to x which is a cell array, and you just forgot to convert the numeric array output'ed by ZEROS into a cell array with NUM2CELL.

The last operation develops result in a comma separated list of cells content (which are 1x3 numeric arrays given my approach), and concatenates it vertically.

[John Doe]

This does exactly what I wanted!!

Thank you Sir for the help! Now it makes more sense to me ^^

[Cedric]

My pleasure!

Just for reference, your approach works too with a call to NUM2CELL:

 >> out=(cellfun(@(x)cat(2,x,num2cell(zeros(1,maxLength-length(x)))),A,'UniformOutput',false))
 out =
  3×1 cell array
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}

 >> cell2mat(vertcat(out{:}))
 ans =
     5     6     0
     7     0     0
     8     9     3

[John Doe]

I do have another question which seems very silly.

My next step after having the matrix is to make a table, but even though I have multiple columns, my table seems to have 1 single column instead of 8.

I have attached my out table here. I guess my question is, how do I get 8 columns instead of 1 under a single heading??

Thank You!

[John Doe]

I realized that array2table works for this!!