[R] Creating new instances from original ones

Prof. Dr. Matthias Kohl Matthias.Kohl at stamats.de
Sun Mar 31 11:18:44 CEST 2013


see function SMOTE in package DMwR
hth
Matthias

On 31.03.2013 10:46, Nicolás Sánchez wrote:
> I have a question about data mining. I have a dataset of 70 instances with
> 14 features that belong to 4 classes. As the number of each class is not
> enough to obtain a good accuracy using some classifiers( svm, rna, knn) I
> need to "oversampling" the number of instances of each class.
>
> I have heard that there is a method to do this. It consists in generating
> these new instances as follows:
>
> new_instance <---- original_instance + u(epsilon)
>
>   U(epsilon) is a uniform number in the range [-epsilon,epsilon] and this
> number is applied to each feature of the dataset to obtain a new instance
> without modified the original class.
>
> Anybody has used this method to "oversampling" his data? Anybody has more
> information about it?
>
> Thanks in advance!
>
> 	[[alternative HTML version deleted]]
>
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-- 
Prof. Dr. Matthias Kohl
www.stamats.de



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