Add trees to an ensemble

Add additional trees to an existing ensemble of trees.

# S3 method for class 'randomForest'
grow(x, how.many, ...)

Arguments

x

an object of class randomForest, which contains a forest component.

how.many

number of trees to add to the randomForest object.

...

currently ignored.

Value

An object of class randomForest, containing how.many additional trees.

Note

The confusion, err.rate, mse and rsq components (as well as the corresponding components in the test compnent, if exist) of the combined object will be NULL.

See also

combine, randomForest

Author

Andy Liaw andy_liaw@merck.com

Examples

data(iris)
iris.rf <- randomForest(Species ~ ., iris, ntree=50, norm.votes=FALSE)
iris.rf <- grow(iris.rf, 50)
print(iris.rf)
#> 
#> Call:
#>  randomForest(formula = Species ~ ., data = iris, ntree = 50,      norm.votes = FALSE) 
#>                Type of random forest: classification
#>                      Number of trees: 100
#> No. of variables tried at each split: 2
#>