[R] prediction error in ROCR package when sampled y consists of only one class

[Saeed Abu Nimeh]

Try performing stratified sampling when doing cv.
cran.r-project.org/web/packages/ipred

On Fri, Apr 15, 2011 at 11:00 AM, Soyeon Kim <yunni0731 at gmail.com> wrote:
> Dear R users,
>
> Hi. I am using prediction function in ROCR package.
> y consists of two classes 0 and 1.
> However, since I am using cross-validation, a sampled small number of
> y may consist of only one class
>>y
>  [1] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> In this case, prediction function gives an error:
> Error in prediction(predic, y) : Number of classes is not equal to 2.
> ROCR currently supports only evaluation of binary classification tasks.
>
> How can I solve this problem?
>
> Thank you,
> Soyeon Kim
>
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