[R] creating a list of lists

[Eric Archer]

Howabout using 'lapply'?

forest <- lapply(1:10, function(level) {
  # do some other things here
  # create and return a random forest
   randomForest(x = x.level, y = z.level, ntree = trees)
})

# give meaningful names
names(forest) <- paste("level", 1:10, sep = "_")
 
Paul Boutros wrote:
> Hello,
>
> I'm trying to create a series of randomForest objects, basically in a  
> loop like this:
>
> forests <- list();
>
> for (level in 1:10) {
>
>           # do some other things here
>
> 	# create a random forest
> 	forest <- randomForest(
> 		x = x.level,
> 		y = z.level,
> 		ntree = trees
> 		);
>
> 	forests <- c(forests, forest);
>
> 	}
>
>
> But instead of creating a list of 10 forests, this creates a list of  
> 180 elements, 18 for each forest.  Is there a way to create a list of  
> randomForest objects for use later on in code like:
>
> for (forest in forests) {
>          values <- predict(forest, data);
>          # do things with these predicted values
>          }
>
> Sincerely,
> Paul
>
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>   


-- 

Eric Archer, Ph.D.
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