MATLAB: How to concatenate 3D arrays from multiple .mat files

3d matrixconcatenation

I have 360 archives.mat, each with a variable 'A', of size 1800x400x1. I would like to concatenate these arrays in the third dimension, ie I would like an 'A1' of size 1800x400x360. For this I tried two things: 1) I used the 'cat' command (as in the code below), but it just saved the last array:
          d=dir('test/*.mat');%test is the name of my directory where these files are stored
          nn=length(d);
          A1=[];
          for ii=1:nn
             eval(['load teste/',d(ii).name]) 
             disp(d(ii).name)
             A1=cat(3,A);
          end
2) I tried to use [], but it only concatenates in the first or second dimension:
         d=dir('test/*.mat');
         nn=length(d);
         A1=[];
         for ii=1:nn
            eval(['load test/',d(ii).name]) 
            disp(d(ii).name)
            A1=[A1;A];
          end
Anyone have any suggestions on how to solve this? Thanks.

Best Answer

A1 = cat(3, A1, A);
but you could also use
A1(:,:,ii) = A;
and you could pre-allocated, like
          d=dir('test/*.mat');%test is the name of my directory where these files are stored
          nn=length(d);
          for ii=1:nn
             eval(['load teste/',d(ii).name]) 
             disp(d(ii).name)
             if ii == 1
               A1 = zeros(size(A,1), size(A,2), nn);
             end
             A1(:, :, ii) = A;
          end
However, you should avoid using eval:
          projectdir = 'test';
          d = dir( fullfile(projectdir, '*.mat') );
          nn = length(d);
          for ii=1:nn
             load( fullfile(projectdir, d(ii).name) ) 
             disp(d(ii).name)
             if ii == 1
               A1 = zeros(size(A,1), size(A,2), nn);
             end
             A1(:, :, ii) = A;
          end
and you should avoid using load() without any output:
          projectdir = 'test';
          d = dir( fullfile(projectdir, '*.mat') );
          nn = length(d);
          for ii=1:nn
             datastruct = load( fullfile(projectdir, d(ii).name), 'A' );
             A = datastruct.A; 
             disp(d(ii).name)
             if ii == 1
               A1 = zeros(size(A,1), size(A,2), nn);
             end
             A1(:, :, ii) = A;
          end
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