How to split a cell 1x1 in Matlab?

Question

Let's say I have a 1x1 cell with this value : 'atcatcaaca' . My goal is :

1. Add 1 to 5 'a' beside any 'a'.

2. Add 1 to 10 'c' beside any 'c'.

3. Add a random number of 'g' beside any 'g'.

4. Add a random number of 't' beside any 't'.

   For example i have 'atcatcaaca'.My goal is to make it like:'aaaattttcccaattttccaaaaaaaaaacccccccccaa'

My thought is to take the value cell and split it somehow in a matrix: a | t | a | t | c |a |a | c | a. Is it possible?And if it is ,how?

The code is :

filename = fullfile(matlabroot,'virus_nucleotitde2.dat');

Z = readtable(filename);

S = table2cell(Z);

num_rows = size (Z,1);
num_cols = size (Z,2);
for i=1:1:num_rows
   for j=1:1:num_cols
    B = S(i,j);
    a=0;
    c=0;
    g=0;
    t=0;


B{1} = num2cell(B{1});

n = randi(6);  % Random number between 1 and 6
B{1} = strrep(B{1} , 'a' , repmat('a' , 1, n));

n = randi(11);  % Random number between 1 and 11
B{1} = strrep(B{1} , 'c' , repmat('c' , 1, n));

n = randi(11); 
B{1} = strrep(B{1} , 'g' , repmat('g' , 1, n));

n = randi(11); 
B{1} = strrep(B{1} , 't' , repmat('t' , 1, n));

    end

end

Answer 1

Inside the cell, there is a char that you can access with curly brackets:

 S = {'ataggatag'};
 B = S{1};
 disp(B)

Then, strrep is your friend:

n = randi(6);  % Random number between 1 and 6
B = strrep(B , 'a' , repmat('a' , 1, n));

n = randi(11);  % Random number between 1 and 11
B = strrep(B , 'c' , repmat('c' , 1, n));

n = randi(11); 
B = strrep(B , 'g' , repmat('g' , 1, n));

n = randi(11); 
B = strrep(B , 't' , repmat('t' , 1, n));

Then put it back into the cell

S{1} = B;
disp(S)

Note that I used 6 as maximum number of 'a's because strrep is going to replace the original a, not adding letters beside it as you asked.

EDIT:

Following OP's edit, here is your solution:

S = {'ataggatag'};

num_rows = size (S,1);
num_cols = size (S,2);

for i=1:1:num_rows
   for j=1:1:num_cols
        n = randi(6);  % Random number between 1 and 6
        S{i,j} = strrep(S{i,j} , 'a' , repmat('a' , 1, n));

        n = randi(11);  % Random number between 1 and 11
        S{i,j} = strrep(S{i,j} , 'c' , repmat('c' , 1, n));

        n = randi(11); 
        S{i,j} = strrep(S{i,j} , 'g' , repmat('g' , 1, n));

        n = randi(11); 
        S{i,j} = strrep(S{i,j} , 't' , repmat('t' , 1, n));
    end

end

disp(S)