MATLAB: How to flatten and split and concatenate arrays in several files

Question

Hello.

I want to flatten and split and concatenate arrays in several files.

For example,

I have several datasets (237 x 40, 238 x 40, 239 x 40 ….)

1. I want to flatten each dataset

(237 x 40 -> 1 x 9480 , 238 x 40 => 1 x 9520, 239 x 40 = > 1 x 9560)

2. I want to split each datasets to minimum length among datasets.

1 x 9480, 1 x 9480, 1 x 9480

3. concatenate (3 x 9480)

I can do as several codes, but I have lots of data.

So I want to reduce the code.

clear all
close all
X = csvread('boxing/boxing50.csv');
Y = csvread('boxing/boxing51.csv');
Z = csvread('boxing/boxing52.csv');
% flatten
X = reshape(X,[],1);
Y = reshape(Y,[],1);
Z = reshape(Z,[],1);
% find the minimum and split to the minimum length
X = X(:,1:9480)
Y = Y(:,1:9480)
Z = Z(:,1:9480)
% concatenate
All = [X; Y; Z]

Answer 1

I think the following code can do that task:

By the way, your code will output 28440-by-1 (28440 = 9480 x 3), not the 3-by-9480. So the following code will generate N-by-1 array.

% Create the list of csv files
s = dir('boxing/*.csv');
% Read from each csv file
c = cell(numel(s),1);
for kk = 1:numel(s)
  filePath = fullfile(s(kk).folder,s(kk).name);
  x = csvread(filePath);
  c{kk} = x(:);
end
% Find the minumul length
len = cellfun(@numel,c);
minLen = min(len);
% Delete minLen+1:end for each array in cell
c = cellfun(@(x) x(1:minLen),c,'UniformOutput',false);
% Concatenate them
All = cell2mat(c);