Predict group membership in each tree of the forest

[FridljDa]

Hi, I am interested in using GRF to predict the group membership for each tree. Below the code using randomForestSRC::rfsrc as reference to what I had in mind.

Example code

# simulate training data
n <- 500
p <- 3
X <- matrix(rnorm(n * p), n, p)
Y <- X[, 1] * rnorm(n)
#as data frame
df_train <- data.frame(Y,X)

#simulate small testing set 
X_test <- matrix(rnorm(5*p), 5, p)
df_test <- data.frame(X_test)

#Using randomForestSRC
src_forest <- randomForestSRC::rfsrc(Y ~ X1+X2+X3,
        data = df_train)

predict_groups <- stats::predict(src_forest, df_test, membership = TRUE)$membership 
predict_groups <- as.data.frame(predict_groups)
head(predict_groups)

Returns a data frame with 5 rows and ntrees columns. Each column corresponds to a tree. An entry corresponds to which node leaf the test set lands in.

#Using GRF
grf_forest <- grf::regression_forest(X, Y)
#r.pred <- stats::predict(grf_forest, X, membership = TRUE)

Would something as above work with GRF?

Thank you in advance!

[erikcs]

Hi @FridljDa, you can do something similar with get_tree and get_leaf_node

[FridljDa]

Thank you so much, this is what I was looking for!