Weka_filters {RWeka} | R Documentation

## R/Weka Filters

### Description

R interfaces to Weka filters.

### Usage

    Normalize(formula, data, subset, na.action, control = NULL)
    Discretize(formula, data, subset, na.action, control = NULL)

### Arguments

`formula` | a symbolic description of a model. Note that for unsupervised filters the response can be omitted.
`data` | an optional data frame containing the variables in the model.
`subset` | an optional vector specifying a subset of observations to be used in the fitting process.
`na.action` | a function which indicates what should happen when the data contain `NA`s.
`control` | an object of class `Weka_control`, or a character vector of control options, or `NULL` (default). Available options can be obtained on-line using the Weka Option Wizard `WOW`, or the Weka documentation.

### Details

`Normalize` implements an unsupervised filter that normalizes all instances of a dataset to have a given norm. Only numeric values are considered, and the class attribute is ignored.

`Discretize` implements a supervised instance filter that discretizes a range of numeric attributes in the dataset into nominal attributes. Discretization is by Fayyad & Irani's MDL method (the default).

Note that these methods ignore nominal attributes, i.e., variables of class `factor`.

### Value

A data frame.

### References

U. M. Fayyad and K. B. Irani (1993). Multi-interval discretization of continuous-valued attributes for classification learning. Thirteenth International Joint Conference on Artificial Intelligence, 1022–1027. Morgan Kaufmann.

I. H. Witten and E. Frank (2005). Data Mining: Practical Machine Learning Tools and Techniques. 2nd Edition, Morgan Kaufmann, San Francisco.

### Examples

    ## Using a Weka data set ...
    w <- read.arff(system.file("arff","weather.arff",
                   package = "RWeka"))

    ## Normalize (response irrelevant)
    m1 <- Normalize(~., data = w)
    m1

    ## Discretize
    m2 <- Discretize(play ~., data = w)
    m2

[Package RWeka version 0.4-1 Index]