I really need a R expert for help.
I just installed the package "rpart" successfully but I got the following error message when I ran "rpart".
treemodel <- rpart(Species~., data=iristrain)
Error in rpart(Species ~ ., data = iristrain) :
could not find function "rpart
What should I do in order to run the package "rpart"? It is necessary to modify the content in "Renviron" file? However, I cannot find the "Renivron" file in Windows. What should I do in order to create the "Renviron" file in Windows?