# tree = 500
oob.err1 = numeric(15)
for (mtry in 1:15) {
  fit1 = randomForest(lable ~ .-user_id -product_id, data = train_2, mtry = mtry)
  oob.err1[mtry] = fit1$err.rate[500]
  cat('We are performing iteration', mtry, '\n')
}

plot(1:15, oob.err11, pch = 16, type = 'b',
     xlab = 'Variance Cosidered at Each Split',
     ylab = 'OOB Mean Squared Error',
     main = '1_Random Forest OOB Error Rates\nby # of Variables')
# variane important:
varImpPlot(fit1)
oob.err1[4]