signorm {dprep} | R Documentation

## Sigmoidal Normalization

### Description

Function that performs sigmoidal normalization.

### Usage

    signorm(data)

### Arguments

`data` | the dataset to be normalized, including classes

### 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 normalized data set complete with classes rejoined.

### Value

`sigdata` | original dataset normalized

### Author(s)

Caroline Rodriguez and Edgar Acuna

### 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)

[Package dprep version 1.0 Index]