R help - Feb 2013 - caret: Errors with createGrid for rf (randomForest)

When I try to crate a grid of parameters for training with caret I get
various errors:
------------------------------------------------------------
> my_grid <- createGrid("rf")
Error in if (p <= len) { : argument is of length zero
> my_grid <- createGrid("rf", 4)
Error in if (p <= len) { : argument is of length zero
> my_grid <- createGrid("rf", len=4)
Error in if (p <= len) { : argument is of length zero

The documentation for createGrid says:
------------------------------------------------------------
This function creates a data frame that contains a grid of
     complexity parameters specific methods.
Usage:
       createGrid(method, len = 3, data = NULL)
Arguments:
  method: a string specifying which classification model to use. See
          'train' for a full list.
     len: an integer specifying the number of points on the grid for
          each tuning parameter.
    data: the training data (only needed in the case where the 'method'
          is 'cforest', 'earth', 'bagEarth',
'fda', 'bagFDA', 'rpart',
          'svmRadial', 'pam', 'lars2', 'rf' or
'pls'). The outcome
          should be in a column called '.outcome'.


and gives the following examples:
------------------------------------------------------------
     createGrid("rda", 4)
     createGrid("lm")
     createGrid("nnet")

     ## data needed for SVM with RBF:
     ## Not run:

     tmp <- iris
     names(tmp)[5] <- ".outcome"
     head(tmp)
     createGrid("svmRadial", data = tmp, len = 4)
     ## End(Not run)


What I am doing wrong?

Also, what is the connection between len  above and tuneLength in the
argument for train?

Thanks,

James

	[[alternative HTML version deleted]]

On Feb 12, 2013, at 10:53 AM, James Jong wrote:
> When I try to crate a grid of parameters for training with caret I get
> various errors:
> ------------------------------------------------------------
>> my_grid <- createGrid("rf")
> Error in if (p <= len) { : argument is of length zero
> 
>> my_grid <- createGrid("rf", 4)
> Error in if (p <= len) { : argument is of length zero
> 
>> my_grid <- createGrid("rf", len=4)
> Error in if (p <= len) { : argument is of length zero
> 
> The documentation for createGrid says:
> ------------------------------------------------------------
> This function creates a data frame that contains a grid of
>     complexity parameters specific methods.
> Usage:
>       createGrid(method, len = 3, data = NULL)
> Arguments:
>  method: a string specifying which classification model to use. See
>          'train' for a full list.
>     len: an integer specifying the number of points on the grid for
>          each tuning parameter.
>    data: the training data (only needed in the case where the
'method'
>          is 'cforest', 'earth', 'bagEarth',
'fda', 'bagFDA', 'rpart',
>          'svmRadial', 'pam', 'lars2', 'rf'
or 'pls'). The outcome
>          should be in a column called '.outcome'.
Looking at that example, my first guess would be that your call is missing a
proper 'data' argument. It says one is needed if the method is
'rf'.

-- 
david.

> 
> 
> and gives the following examples:
> ------------------------------------------------------------
>     createGrid("rda", 4)
>     createGrid("lm")
>     createGrid("nnet")
> 
>     ## data needed for SVM with RBF:
>     ## Not run:
> 
>     tmp <- iris
>     names(tmp)[5] <- ".outcome"
>     head(tmp)
>     createGrid("svmRadial", data = tmp, len = 4)
>     ## End(Not run)
> 
> 
> What I am doing wrong?
> 
> Also, what is the connection between len  above and tuneLength in the
> argument for train?
> 
> Thanks,
> 
> James
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
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David Winsemius
Alameda, CA, USA