How to create more cells within a cell in a cell array?

I have a cell array which only consists of numeric values. Hence, there are only numeric values in one cell. However, I need to change some of this values to strings. I tried to do so but I ended up with "NaN"s instead of my string value. I'm guessing the only way to approach this is for all values in a cell to be stored in their own 1 x 1 cell array. So a cell array within a cell array? This is the code used to create the cell array.

 lat = coordinates(:,2); % x coordinates
 lon = coordinates(:,3); % y coordinates

 % create nested for loop 
 % create nested for loop
 i_vector=103.6:(1/75):104;
 j_vector=1.25:(1/120):1.5;
 stns=cell(length(i_vector),length(j_vector)); % 31 x 31 cell array 

 for i = 1:(length(i_vector)-1)
    % you can't access element end+1
    for j = 1:(length(j_vector)-1)
        % index = logical indexing vector
        index = (lat > i_vector(i)) ...
            & (lat < i_vector(i+1)) ...
            & (lon > j_vector(j)) ...
            & (lon < j_vector(j+1)) ;
        stns{i,j} = coordinates(index,1); % stn number

    end
end

So for example, all the values in stns{21,8} and all other cells should be stored in a 1 x 1 cell array right. How do I achieve this?

Answer 1

[Guillaume]

Notwithstanding that I need to change some of these values to strings sounds very iffy (an arbitrary mix of numbers and strings is not a good idea), you can simply convert a matrix into a cell array with num2cell, so change your code to:

stns{i,j} = num2cell(coordinates(index,1)); % stn number

Note that it will not create a 1x1 cell array but an mxn cell array (same size as the matrix) where each cell contains a 1x1 matrix (a scalar). Individual cells can then be changed to strings if desired.

But again, mixing numbers and strings arbitrarily does not sound like a good idea. What exactly are you trying to achieve?