Package teamwork :: Package math :: Module id3

Module id3

This module contains the functions for calculating the information gain of a dataset as defined by the ID3 (Information Theoretic) heuristic.

Functions

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dict

frequency(data, attr)
Computes the histogram over values for the given attribute

source code

entropy(data, target_attr)
Calculates the entropy of the given data set for the target attribute.

source code

gain(data, attr, target_attr)
Calculates the information gain (reduction in entropy) that would result by splitting the data on the chosen attribute (attr).

source code

Function Details

[hide private]

frequency(data, attr)

source code

Computes the histogram over values for the given attribute

Parameters:

data (dict[]) - the data to be analyzed
attr - the attribute to be analyzed

Returns: dict

a dictionary of frequency counts, indexed by attribute values

Warning: assumes all fields have the same number of possible values