An implementation of the Hare-Niemeyer (also known as Hamilton or largest remainder) method. Parliament seat allocation algorithm used in multiple countries around the world.

Attention: Since some countries use a modification of the algorithm instead of this vanilla version, you should check your country's electoral legislature. Furthermore, I don't take any responsibility for the accuracy of the calculated numbers, even though I'm pretty confident with my implementation.

npm install hare-niemeyer

This package is ESM only.

import hareNiemeyer from 'hare-niemeyer'

const electionResults = { // number of votes per party
	socialists: 130755,
	conservatives: 102068,
	liberals: 34012,
	greens: 31090,
	crazypeople: 11111
}
const seats = 420 // number of seats to be distributed

const parliament = hareNiemeyer(electionResults, seats, draw=true)

The parliament variable will look like this:

{
	"socialists": 178,
	"conservatives": 139,
	"liberals": 46,
	"greens": 42,
	"crazypeople": 15
}

The draw option changes the behaviour of the algorithm in case of equal quota remainders for multiple parties. Usually, in this case the elections administrator would draw by lot which party gets the remaining seat. The script does this for you if the draw option is true or not set at all (default behaviour). If you change the option to false, the script will return the raw quotas for the involved parties instead:

const electionResults = { // number of votes per party
	socialists: 10,
	conservatives: 15,
	liberals: 1,
	greens: 4
}
const seats = 100 // number of seats to be distributed

const parliament = hareNiemeyer(electionResults, seats, false)

In this case, the parliament variable looks like this:

{
	"socialists": 33.333333333333,
	"conservatives": 50,
	"liberals": 3.333333333333,
	"greens": 13.333333333333
}

• sainte-lague - Sainte-Laguë / Webster / Schepers method
• DHondt – D'Hondt method

If you found a bug or want to propose a feature, feel free to visit the issues page.