Calculating RMSE

Given an array of predicted and reference values, you may want to calculate the root mean square error (also called RMSD).:

validation = c(2.2, 3.3, 4.4, 5.5)

predicted = c(2.1, 3.5, 4.2, 5.6)

error <- validation - predicted

rmse <- sqrt(mean(error^2))

print(rmse)