utility-function-extractor/packages/utility-tools

Utility Tools

This package contains a series of utilities to work with the utility functions produced by this utility function extractor.

Built with

• Squiggle
• Nodejs
• Plain js

Getting started

Installation

yarn add utility-tools

then in your file:

import { mergeSort, findPaths, aggregatePaths } from "utility-tools";

Usage

You can find an example how to use and concatenate these functions in /src/example.js, as well as an example of the input format needed in the input folder.

Interface

Merge sort (mergeSort)

Given a list of elements and a list of utilitity comparisons, sort the list. If there are not enough comparisons to implement the merge sort algorithm, return one of the missing comparisons.

Gotcha: The list of elements has to be the same list, and in the same order, as that produced when initially doing the comparisons. This is because the merge-sort algorithm depends on the initial order of the list.

Find Paths (findPaths)

Given an (ordered) list of elements and a list of utility comparisons, find all possible monotonous paths from each element to each other. A monotonous path is a path that is either all increasing or all decreasing, relative to the ordering given.

Note: Some elements will have many more paths than others.

Note: The findPaths.js file has a few un-used functions which should make it easier to understand the code.

Aggregate paths (aggregatePaths)

Given a list of path, aggregate them to finally produce an estimate of the relative utility of each element.

There are two ways of doing this:

• 1. Aggregate the means (expected values) for each path.
  • This method is fast
  • But has the disadvantage the expected value aggregation is tricky, particularly if one of the elements is positive and the other one negative (because then one can't)
• 2. Aggregate the distributions given for each path.

Roadmap

I don't have any additions planned for this repository.

Contact

Feel free to shoot me any questions at nuno.semperelh@protonmail.com