brownhci/WebGazer

Consider different Multidimensional Arrays Implementations

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#37 opened on Jun 12, 2016

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Performancehelp wanted

Description

So after looking through the optimizations of this library, we are more or less at a local minimum when it comes to our naive representation of multidimensional arrays. They are currently untyped and simply use the classic Array of Array implementation. We should consider ways of storing our arrays in alternative ways and possibly typing them to get better performance. There is a case to be made that we might want to implement something similar to NDArray, but doing so it contingent on issue #35 . LU decomposition still takes up a rather large portion of the run time.

Currently here are three areas of optimization to focus on:

  1. track() inside of CLMR tracker
  2. getPupilFeatures()
  3. LUDecomposition() and the entire ridge methods

Optimizing these areas will be important if we want to make it practical to run on mobile.

Some reading on the topic: https://0fps.net/2013/05/22/implementing-multidimensional-arrays-in-javascript/ https://github.com/mikolalysenko/ndarray-experiments

Contributor guide

Tech stack
javascript
Domain
performance
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
JavaScriptunderstanding of multidimensional arraysperformance optimization
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
Explore two linked resources about implementing multidimensional arrays in JavaScript. Evaluate current 'array of arrays' representation in WebGazer. Measure performance bottlenecks in track(), getPupilFeatures(), and LUDecomposition. Consider implementing typed arrays or adopting NDArray like structure, contingent on issue #35.
Consider different Multidimensional Arrays Implementations · brownhci/WebGazer#37 | Good First Issue