R help - Apr 2013 - Working with createFolds

Hello!

I have a question. I am working with createFolds:

folds<- trainControl(method='cv', index=createFolds(data$Score,list =
TRUE))

I need to iterate over folds  to extract the indexes from each fold.

For example, if I do folds$index$Fold01, it contains:

     5 11 17 29 44 50 52 64 65

I need to iterate over each $Fold_i to extract the indexes, but I can't do
it because I don't know how to iterate over the structure folds$index$Fold_i

Any ideas?

Thanks!

	[[alternative HTML version deleted]]

Anyone?
;-)


2013/4/7 Nicolás Sánchez <enikok@gmail.com>
> Hello!
>
> I have a question. I am working with createFolds:
>
> folds<- trainControl(method='cv',
index=createFolds(data$Score,list > TRUE))
>
> I need to iterate over folds  to extract the indexes from each fold.
>
> For example, if I do folds$index$Fold01, it contains:
>
>      5 11 17 29 44 50 52 64 65
>
> I need to iterate over each $Fold_i to extract the indexes, but I can't
do
> it because I don't know how to iterate over the structure
folds$index$Fold_i
>
> Any ideas?
>
> Thanks!
>
	[[alternative HTML version deleted]]

Hello,

You should say from what package are the functions you're using.
 From the help page of createFolds, the return value is "A list or 
matrix of row position integers corresponding to the training data"

So to subset use `[` or `[[`. Try

class(folds$index$Fold_i)

If it's a numeric vector, folds$index$Fold_i[i]
If it's a matrix, folds$index$Fold_i[i, j]
If it's a list, folds$index$Fold_i[[i]]


Hope this helps,

Rui Barradas

Em 07-04-2013 13:24, Nicol?s S?nchez escreveu:
> Hello!
>
> I have a question. I am working with createFolds:
>
> folds<- trainControl(method='cv',
index=createFolds(data$Score,list = TRUE))
>
> I need to iterate over folds  to extract the indexes from each fold.
>
> For example, if I do folds$index$Fold01, it contains:
>
>       5 11 17 29 44 50 52 64 65
>
> I need to iterate over each $Fold_i to extract the indexes, but I can't
do
> it because I don't know how to iterate over the structure
folds$index$Fold_i
>
> Any ideas?
>
> Thanks!
>
> 	[[alternative HTML version deleted]]
>
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