R: The superreduct computation based on RST and FRST

FS.feature.subset.computation {RoughSets} | R Documentation

## The superreduct computation based on RST and FRST

### Description

This function is a wrapper for computing different types of decision superreducts (i.e. attribute subsets which do not lose any information regarding the decisions but are not require to be irreducable).

### Usage

    FS.feature.subset.computation(decision.table,
      method = "greedy.heuristic.superreduct", ...)

### Arguments

`decision.table` | an object of a `"DecisionTable"` class representing a decision table. See `SF.asDecisionTable`.
`method` | a character representing the type of a method to use for computations. See in Section `Details`.
`...` | other parameters corresponding to the chosen `method`.

### Details

Currently, there are implemented three methods that can be used with this function:

- `"greedy.heuristic.superreduct"`: it is a greedy heuristic method which employs several quality measures from RST. See `FS.greedy.heuristic.superreduct.RST`.

- `"quickreduct.frst"`: it is a feature selection function based on the fuzzy QuickReduct algorithm on FRST. See `FS.quickreduct.FRST`.

- `"quickreduct.rst"`: it is a feature selection function based on the RST QuickReduct algorithm. See `FS.quickreduct.RST`.

These methods can be selected by assigning an appropriate value of the parameter `method`. Additionally, `SF.applyDecTable` is provided to generate the new decision table.

### Value

A class `"FeatureSubset"`.

### Author(s)

Andrzej Janusz

### See Also

`FS.greedy.heuristic.superreduct.RST`, `FS.quickreduct.RST`, `FS.quickreduct.FRST`.

### Examples

    ###############################################################
    ## Example 1: generate reduct and new decision table using RST
    ###############################################################
    data(RoughSetData)
    decision.table <- RoughSetData$hiring.dt

    ## generate single superreduct
    res.1 <- FS.feature.subset.computation(decision.table,
                                           method = "quickreduct.rst")

    ## generate new decision table according to the reduct
    new.decTable <- SF.applyDecTable(decision.table, res.1)

    ###############################################################
    ## Example 2: generate reduct and new decision table using FRST
    ###############################################################
    data(RoughSetData)
    decision.table <- RoughSetData$housing7.dt

    ## generate single superreduct
    res.2 <- FS.feature.subset.computation(decision.table,
                                           method = "quickreduct.frst")

    ## generate new decision table according to the reduct
    new.decTable <- SF.applyDecTable(decision.table, res.2)

[Package RoughSets version 1.3-7 Index]