Spliting ground truth data into 70% training, 20% validation and 10% Testingdata

Hi guys

i am looking for spliting data from ground truth file for following code

70% training, 20% validation and 10% Testingdata

load('gTruth.mat')
Fruits = selectLabels(gTruth,{'orange','Apple'});
if isfolder(fullfile('ExperimentData'))
    cd ExperimentData
else
     mkdir ExperimentData
end 
  
 
addpath('ExperimentData');
splitFolder = true;


if splitFolder
    valFolderName = "ExperimentData";
    
    files = dir(fullfile(valFolderName));
    N = length(files);
    tf=randperm(N)>(0.20*N);
    mkdir TrainingData;
    mkdir ValidationData;
    mkdir TestingData;

    for i=3:length(tf)
        files_re = files(i).name;
        if tf(i) == 3
            copyfile (fullfile(valFolderName,files_re),'TrainingData')
        else
            copyfile (fullfile(valFolderName,files_re),'Validation')
        ifelse
            copyfile (fullfile(valFolderName,files_re),'TestingData')

        end
    end
end