# How to save nested cells in mat file

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Sanjana Sankar on 2 Aug 2019
Commented: Sanjana Sankar on 19 Aug 2019
I want to save data in such a way that a cell holds another cell array.
My main table will consist of cells, each of which will hold 24 cell arrays of size 1X63. How to save data in such a manner?
The idea is that I am encoding a words with numbers
For example. If my word is Aalen, A = 1x63 vector, a = 1x63 vector, l = 1x63 vector, e=1x63 vector, n=1x63 vector.
So for each word in my list, I waant to save a vector for each letter in the word.

Rik on 2 Aug 2019
It sounds like you need a 1x24 or 24x1 element cell array, with each containing a 1x63 double array. Why not 26 by the way? Then you would have a cell element for each letter. And is the vector for 'A' the same as for 'a'?
If you convert your char to double, you can easily use them as indices:
%generate a library random as an example
lib=cell(1,26);
for n=1:26
lib{n}=rand(1,63);
end
word='Aalen';
%convert to cell array
ind=lower(word)-'a'+1;%convert to lowercase and map 'a' to 1
output=lib(ind);
Sanjana Sankar on 19 Aug 2019
26 is not appropriate for me because I'm using german alphabets. Hence it is more than 26. In that case, I cannot use 'a'+1.
Rik on 19 Aug 2019
Something like this will still work. You will either have a library with a lot of empty cells, or you need to have an extra lookup table step.

Rik on 19 Aug 2019
The code below is probably what you need (or close to it). If letters are used that are not in the letterlist, then an error will occur, because the ind variable will contain a 0.
%all(?) letters used in German:
letterlist=['a':'z' 'A':'Z' ...
char([196 203 207 214 220 223 228 235 239 246 252])];
%generate a library with random entries as an example
lib=cell(1,numel(letterlist));
for n=1:numel(letterlist)
lib{n}=rand(1,63);
end
word='Aalen';
[~,ind]=ismember(word,letterlist);
output=lib(ind);

#### 1 Comment

Sanjana Sankar on 19 Aug 2019
Thank you Rik! I have to one-hot the letters. But otherwise this code is exactly what I need. I can work with this. :)

You can create nested cell in following manner:
N = 5;
A = {cell(1,N)};
for k = 1:N
A{k} = rand(1,63);
end
You can also convert a string into a cell array of letters the following way:
S = num2cell('Aalen');