How to split data into training/testing sets using sample function

Question

I\'ve just started using R and I\'m not sure how to incorporate my dataset with the following sample code:

sample(x, size, replace = FALSE, prob = NULL)
         


        

Answer 1

My solution is basically the same as dickoa's but a little easier to interpret:

data(mtcars)
n = nrow(mtcars)
trainIndex = sample(1:n, size = round(0.7*n), replace=FALSE)
train = mtcars[trainIndex ,]
test = mtcars[-trainIndex ,]