display.R

# The display command aims to provide a visualisation of the model in
# some form. This will differ from model to model.

cat("=============
Decision Tree
=============

A visual representation of a model can often be more insightful
than the printed textual representation. For a decision tree
model, representing the discovered knowledge as a decision tree, we
read the tree from top to bottom, traversing the path corresponding
to the answer to the question presented at each node. The leaf node
has the final decision together with the class probabilities.
")

suppressMessages(
{
library(rattle)      # Support: normVarNames(), weatherAUS. 
})

load("iris_rpart_caret_model.RData")
model <- m$finalModel

if (Sys.getenv("DISPLAY") != "")
{
  cat("
To display the decision tree press <Enter>: ")
  invisible(readChar("stdin", 1))

  fname <- "rpart_model.pdf"
  pdf(fname)
  fancyRpartPlot(model, sub="")
  invisible(dev.off())
  system(paste("atril --preview", fname), ignore.stderr=TRUE, wait=FALSE)
}

cat("
Close the graphic window using Ctrl-W.
Press Enter to finish: ")
invisible(readChar("stdin", 1))