MATLAB: Extracting name of variables from cell array

cell arrayvariables

Dear All,
I have a cell array combin which contains all possible combinations of 4 elements ('A';'B';'C';'D') taken 3 at a time.
combin = 
      'A'    'B'    'C'
      'A'    'B'    'D'
      'A'    'C'    'D'
      'B'    'C'    'D'
coef = ['A';'B';'C';'D'];
coef = cellstr(coef);
combin = nchoosek(coef,3)
Each letter is also the variable name of a random number vector:
A = rand(10,1); B = rand(10,1); C = rand(10,1); D = rand(10,1);
I would like to obtain a matrix made of vectors A,B,C or D for each row of combin. For instance,
mod1 = [A B C];
...
mod4 = [B C D];
Any help would be highly appreciated.
Best, S.

Best Answer

It will be much easier if we can turn your 'A', 'B', 'C', 'D' into 1, 2, 3, 4. For example,
>> coef = [1;2;3;4];
>> combin = nchoosek(coef, 3)
combin =
       1     2     3
       1     2     4
       1     3     4
       2     3     4
Also assume that we can put vectors {A, B, C, D} into one big matrix (say R). For example,
>> R = rand(10,4)
R =
      0.8147    0.1576    0.6557    0.7060
      0.9058    0.9706    0.0357    0.0318
      0.1270    0.9572    0.8491    0.2769
      0.9134    0.4854    0.9340    0.0462
      0.6324    0.8003    0.6787    0.0971
      0.0975    0.1419    0.7577    0.8235
      0.2785    0.4218    0.7431    0.6948
      0.5469    0.9157    0.3922    0.3171
      0.9575    0.7922    0.6555    0.9502
      0.9649    0.9595    0.1712    0.0344
Then the following one line will create vector mod1,
>> mod1 = R(:, combin(1,:))
mod1 =
      0.8147    0.1576    0.6557
      0.9058    0.9706    0.0357
      0.1270    0.9572    0.8491
      0.9134    0.4854    0.9340
      0.6324    0.8003    0.6787
      0.0975    0.1419    0.7577
      0.2785    0.4218    0.7431
      0.5469    0.9157    0.3922
      0.9575    0.7922    0.6555
      0.9649    0.9595    0.1712
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