Q:

sampsize error in Random Forests

I want to set different sampsize for randomForest in R. I expect to see 3 different RF return, but the error occured in R  "(list) object cannot be coerced to type 'integer'"
and my code is as follows
    sampsize_vect<-vector("list",3)
    sampsize_vect[[1]]<- rep(6670,3)
    sampsize_vect[[2]]<- c(1000)
    sampsize_vect[[3]]<- c(5000,5000)
    for (i in 1:3) {
    RF <- randomForest (x,y,sampsize=sampsize_vect[i],node.size=3,do.trace=FALSE,importance=TRUE,ntree=150,,forest=TRUE)
    print(RF)
    }

Why this happened and how to solve this problem. 

A:

It doesn't have anything to do with the random forests.  You simply used [ when you should have used [[ (or vice versa, I suppose). 
Change sampsize = sampsize_vect[i] to sampsize = sampsize_vect[[i]]].  Always remember, with lists [[ selects an element while [ selects a sub-list.