hrerror = randn(100, 1); % generate some random data
hr_rmse =rms(hrerror) % use rms function
hr_rmse1 = sqrt(mean(hrerror.^2)) % root-mean-square
% Not recommended
hr_rmse2=0;
K = length(hrerror);
for i=1:K
hr_rmse2 = hr_rmse2 + hrerror(i).^2;
end
hr_rmse2 = sqrt(hr_rmse2/K)
