Power-Indices

Power index calculator, for the:

• Banzhaf power index.
• Shapley-Shubik power index.
• Holler-Packel power index.
• Deegan-Packel power index
• Johnston power index.

Installation

In order to install the power index calculator, you can just do the pip install, like this:

sudo pip install power_index_calculator

Usage

First, you need to import the functions, like this

import power_index_calculator as calculator

Then you can use the functions in the file. For example, lets say that we have the weighted game [4;1,2,2,3], where 4 is the quota of the game, and the rest of the vector is the weight of each player i (this is, weight(P1) = 1, weight(P2) = 2, weight(P3) = 2 and weight(P4) = 3), then we can use the calculator like this:

quota = 4
weights = [1,2,2,3]
banzhaf = calculator.banzhaf(weights,quota)
print banzhaf

The output of the example will be:

[0.083, 0.25, 0.25, 0.417]

This is, banzhaf_index(P1) = 0.083, banzhaf_index(P2) = 0.25, banzhaf_index(P3) = 0.25 and banzhaf_index(P4) = 0.417.

One can use the rest of the functions to calculate the shapley-shubik power index, the holler-packel power index, the deegan-packel power index and the johnston power index, like this (taking the same example as before):

quota = 4
weights = [1,2,2,3]
banzhaf = calculator.banzhaf(weights,quota)
shapley = calculator.shapley(weights,quota)
holler = calculator.holler_packel(weights,quota)
deegan = calculator.deegan_packel(weights,quota)
johnston = calculator.johnston(weights,quota)

The output of the example, is summaried in the next table:

License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE.md file for details.