wsrf (version 1.5.47)

combine.wsrf: Combine Ensembles of Trees

Description

Combine two more more ensembles of trees into one.

Usage

combine(...)

Arguments

...

two or more objects of class randomForest, to be combined into one.

Value

An object of class wsrf.

See Also

subset

Examples

  library("wsrf")

  # Prepare parameters.
  ds     <- rattle::weather
  target <- "RainTomorrow"
  vars   <- setdiff(names(ds), c("Date", "Location", "RISK_MM"))
  if (sum(is.na(ds[vars]))) ds[vars] <- randomForest::na.roughfix(ds[vars])
  ds[target] <- as.factor(ds[[target]])
  form <- as.formula(paste(target, "~ ."))
  set.seed(42)
  train.1 <- sample(nrow(ds), 0.7*nrow(ds))
  test.1  <- setdiff(seq_len(nrow(ds)), train.1)

  set.seed(49)
  train.2 <- sample(nrow(ds), 0.7*nrow(ds))
  test.2  <- setdiff(seq_len(nrow(ds)), train.2)
  
  # Build model.
  model.wsrf.1 <- wsrf(form, data=ds[train.1, vars])
  model.wsrf.2 <- wsrf(form, data=ds[train.2, vars])

  
  # Merge two models.
  model.wsrf.big <- combine.wsrf(model.wsrf.1, model.wsrf.2)
  print(model.wsrf.big)
  cl <- predict(model.wsrf.big, newdata=ds[test.1, vars], type="response")
  actual <- ds[test.1, target]
  (accuracy.wsrf <- sum(cl==actual)/length(actual))