R: The entropy measure

X.entropy {RoughSets} | R Documentation

## The entropy measure

### Description

An auxiliary function for the `qualityF` parameter in the `FS.greedy.heuristic.reduct.RST`, `FS.DAAR.heuristic.RST` and `FS.greedy.heuristic.superreduct.RST` functions. It is based on entropy as a measure of information(Shannon, 1948).

### Usage

    X.entropy(decisionDistrib)

### Arguments

`decisionDistrib` | an integer vector corresponding to a distribution of attribute values

### Value

a numeric value indicating entropy of an attribute.

### Author(s)

Andrzej Janusz

### References

C. E. Shannon, "A Mathematical Theory of Communication", Bell System Technical Journal, vol. 27, p. 379 - 423, 623 - 656 (1948).

[Package RoughSets version 1.3-7 Index]