I have 400 images in my dataset(images).I want to split the dataset into 80% for training and 20% for testing.the below attached code works but , test_idx is empty?why?
train_idx contains 320 images.test_idx is empty.
faceDatabase = imageSet('facedatabaseatt','recursive');
N = 400;
idx = 1:N ;
PD = 0.80 ;
train_idx = idx(1:round(PD*N));
test_idx = idx(round(PD*N)+1:end,:) ;