I am very new to machine learning. I am trying to explore fitting random forests with the ranger library in R. My dependent variable is continuous - so it would be a regression tree (and not just classification). Upon trying out the functions, I have noticed that there seems to be a discrepancy between ranger and predict ranger. The following lines result in different predictions in results
and results_alternative
:
rf_reg <- ranger(formula = y ~ ., data = training_df)
results <- rf_reg$predictions
results_alterantive <- predict(rf_reg, data = training_df)$predictions
Could anybody please explain why there is a discrepancy and what is causing it? Which one is correct? I have tried it with classification on iris
data and that seemed to give the same results. Many thanks!