function [pcaDataset] = myPCA(dataset)

% this function applies the PCA transformation

% firstly standardize data
columnStdDevs = std(dataset(:,1:(size(dataset,2)-1)));
standardizedData = dataset(:,1:(size(dataset,2)-1)) ./ repmat(columnStdDevs,size(dataset,1),1); 

 % apply PCA to get coefficients
[coefs,scores,variances,t2] = princomp(standardizedData); 
% multiply actual data with coefficients
pcaDataset = [(standardizedData * coefs),dataset(:,size(dataset,2))];

end