# How to cell array of string to 3D matrix?

4 views (last 30 days)
Danupon Subanapong on 15 Nov 2018
I have a cell array with size 200x1 with each cell having a string array 12000x1 cell. Example of string array with size 12000x1 will be in the attached file. How can i convert this cell into a 3d numeric matrix array of size 12000x5x200 ?? Thank you in advance.

Stephen Cobeldick on 15 Nov 2018
"I have a cell array with size 200x1 with each cell having a string array 12000x1 cell"
But what you uploaded is a 12000x1 cell array, where each cell contains a character vector.:
>> size(AB)
ans = 12000 1
>> all(cellfun('isclass',AB,'char'))
ans = 1
Danupon Subanapong on 15 Nov 2018
I am sorry. please refer to the new attached file.

Stephen Cobeldick on 15 Nov 2018
Edited: Stephen Cobeldick on 15 Nov 2018
This converts your supplied cell array (attached) into a numeric array:
>> C = cellfun(@(s)sscanf(s,'%f'),AB,'uni',0);
>> A = cat(3,C{:});
>> size(A)
ans =
5 1 12000
Note that your data description does not match the data in your .mat file.

Stephen Cobeldick on 15 Nov 2018
Two methods that work with the data in your second example file.
Method one: cellfun and cellmat:
>> F = @(s) sscanf(s,'%f',[1,Inf]);
>> A = cell2mat(cellfun(F,cat(3,BB{:}),'uni',0));
>> size(A)
ans =
12000 5 200
Method two: sprintf, reshape and permute:
>> C = [BB{:}];
>> B = sscanf(sprintf('%s\v',C{:}),'%f');
>> B = permute(reshape(B,[5,12000,200]),[2,1,3]);
>> size(B)
ans =
12000 5 200
Method two is quite possibly faster. Comparing the outputs:
>> isequal(A,B)
ans = 1
Danupon Subanapong on 15 Nov 2018
It works. Thank you so much.