Reputation: 1223
When not specifying the ntree
count in a caret "rf" model, I am having a difficult time finding how many trees were used in the model.
Here is the code I am using to train my model:
fitControl <- trainControl(
method = "cv",
number = 3,
savePredictions = "final",
classProbs = T,
summaryFunction = twoClassSummary,
sampling = "down")
set.seed(3219)
rf_model_down <- train(Class ~ .,
data = train_data,
method ='rf',
tuneLength = 2,
trControl = fitControl,
metric = "ROC")
using the print(rf_model_down)
function, I am able to see what the mtry
was, but it doesn't tell us the ntree
count used.
print(rf_model_down)
# Random Forest
#
# 10000 samples
# 94 predictor
# 2 classes: 'Fraud', 'notFraud'
#
# No pre-processing
# Resampling: Cross-Validated (3 fold)
# Summary of sample sizes: 6667, 6666, 6667
# Addtional sampling using down-sampling
#
# Resampling results across tuning parameters:
#
# mtry ROC Sens Spec
# 2 0.7401603 0.7691257 0.5717070
# 94 0.7449104 0.6814208 0.6641911
#
# ROC was used to select the optimal model using the largest value.
# The final value used for the model was mtry = 94.
Thanks, in advance, for what is most likely an easy answer that I'm having a difficult time finding...
Upvotes: 2
Views: 785
Reputation: 48201
Inspecting str(rf_model_down)
shows that we can use
rf_model_down$finalModel$ntree
Upvotes: 3