dprep (version 3.0.2)

signorm: Sigmoidal Normalization

Description

Function that performs sigmoidal normalization.

Usage

signorm(data)

Arguments

data

The dataset to be normalized, including classes

Value

sigdata

Original dataset normalized

Details

This method transforms the input data nonlinearly into [-1,1] using a sigmoid function. The original data is first centered about the mean, and then mapped to the almost linear region of the sigmoid. Is especially appropriate when outlying values are present.

Removes classes before normalization, and returns the normalized data set complete with classes rejoined.

References

Hann, J., Kamber, M. (2000). Data Mining: Concepts and Techniques. Morgan Kaufman Publishers.

Examples

#---- Sigmoidal Normalization ---
data(vehicle)
vehicle.signorm=signorm(vehicle)
op=par(mfrow=c(2,1))
plot(vehicle[,1])
plot(vehicle.signorm[,1])
par(op)