CODEWITHSUNDEEP
rfunction
Knight
Knight

Reputation: 363

Passing list of values as parameters to a function in R

I have two lists

   a=expand.grid(mtry=c(8))
   b=expand.grid(usekernel=c(8), fL=c(9))
   c=expand.grid(usekernel=c(8), fL=c(9))
   list_1<- list(a,b,c)
   list_2<- list("rf","nb","nb2")

And I have a function as follows

  func(TrainData, TrainClasses,method,tune)
  if method is "rf" then tune=a, if "nb" then tune=b, nb2=c

Instead of writing the method and tune every time, I want to pass the lists(list_1 and list_2) and invoke the "func" function for every method. I tried for loop, but its not giving the desired results.

Reproducible code

library(caret)
data(iris)
TrainData <- iris[,1:4]
TrainClasses <- iris[,5]
method<- c("rf")
tune<-expand.grid(mtry=c(8))

func<- function(TrainData, TrainClasses,method,tune )
{
 k <- train(TrainData, TrainClasses,
               method = method,
               preProcess = c("center", "scale"),
               tuneLength = 10,
               tuneGrid = tune,
               trControl = trainControl(method = "cv"))
 k
}

func(TrainData, TrainClasses,method, tune)

So, in the above function, I'm passing one method and its tune, but now I want to pass the list of methods one after the other with their respective tune instead of giving method and its tune every time, I want to execute all the 3 methods at once. Like I said before, my list_2 contains methods and list_1 contains respective tunes.

My code:

 for(i in 1:3){
     tune_e=c(list(TrainData=TrainData,TrainClasses=TrainClasses),list_2[i],list_1[i])
     do.call('func',tune_e)
 }

Upvotes: 2

Views: 2675

Answers (1)

CJB
CJB

Reputation: 1809

Excuse me if I haven't quite grasped what you want. Would this work?

list_1 <- c(a,b,c); list_2 <- c("rf","nb","nb2")
for(i in 1:3){
    func(TrainData, TrainClasses, list_2[i], list_1[i])
}

The problem is with the lists. If they are simply vectors, then it should work. Do they need to be lists for another reason? If so:

list_1 <- list(a,b,c); list_2 <- list("rf","nb","nb2")
for(i in 1:3){
    func(TrainData, TrainClasses, list_2[[1]][i], list_1[[1]][i])
}

The double square brackets are important.

Upvotes: 2

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