Splitting a 1 x1 cell array every three characters?

I have a 1 x 1 cell array that is a short DNA codon sequence. I want to turn this sequence into a matrix with each column containing a single codon. How can I split this long string every three characters, and make it into a matrix?

Answer 1

[Image Analyst]

A 1x1 cell array is not much of an array - there's just one element! Anyway, try this:

stringInside = ca{1}; % Extract string from inside the cell array.
numChars = length(stringInside) % Get number of characters in the string.  Must be a multiple of 3
% Reshape into a 3 column character array.
charArray = reshape(stringInside, numChars/3, 3)

Answer 2

[Star Strider]

This is how I would do it:

B = {'A' 'T' 'C' 'G'};                  % Bases
I = randi(4, 1, 12);                    % Sequence Index
S = {B(I)};                             % Linear Sequence
S{:}                                    % Display (Optional)
CM = reshape(S{:}, 3, [])               % Codons In Columns

ans = 
    'G'    'G'    'G'    'A'    'T'    'A'    'A'    'T'    'C'    'C'    'C'    'C'

CM = 
    'G'    'A'    'A'    'C'
    'G'    'T'    'T'    'C'
    'G'    'A'    'C'    'C'

This is random, so running it will give different results each time, but the codons will match the order of those in the linear sequence.