# hyperbolic-canvas

> The Poincaré disk model of the hyperbolic plane on the HTML canvas.

Latest version **1.0.1** (published 2019-05-19) · MIT license · 0 weekly downloads

## Install

```sh
npm install hyperbolic-canvas
pnpm add hyperbolic-canvas
yarn add hyperbolic-canvas
bun add hyperbolic-canvas
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 1.0.1 |
| Published | 2019-05-19 |
| First published | 2019-05-19 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 65.4 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 53 |
| Author | Nick Barry |
| Maintainers | itsnickbarry |
| Keywords | hyperbolic, geometry, canvas, wow, visualization, non-euclidean, poincare, math, maths |

## Links

- npm: https://www.npmjs.com/package/hyperbolic-canvas
- Repository: https://github.com/itsnickbarry/hyperbolic-canvas
- Homepage: https://github.com/itsnickbarry/hyperbolic-canvas#readme
- Issues: https://github.com/itsnickbarry/hyperbolic-canvas/issues
- npm.io page: https://npm.io/package/hyperbolic-canvas

## Recent versions

- 1.0.1 (latest) — 2019-05-19
- 1.0.0 — 2019-05-19

## README

# Hyperbolic Canvas

A Javascript implementation of the [Poincaré disk model](https://en.wikipedia.org/wiki/Poincar%C3%A9_disk_model) of the hyperbolic plane, on an HTML canvas.

Usage examples can be found on the [project site](https://ItsNickBarry.github.io/hyperbolic-canvas).

## Scope

This library prioritizes the visualization of hyperbolic geometry over precise mathematical calculation.  Due to the less-than-infinite precision of floating-point numbers, and because certain trigonometric functions are [ill-conditioned](https://en.wikipedia.org/wiki/Condition_number), these goals are often at odds.

### Accuracy Thresholds

The arbitrary constants `HyperbolicCanvas.INFINITY` and `HyperbolicCanvas.ZERO` have been defined for use in internal comparisons in place of `Infinity` and `0`, respectively.  Their values may be overridden, but increased accuracy will tend to lead to more unpredictable behavior.

### Jasmine Specs

This library uses [Jasmine specs][jasmine] to validate the code and prevent regressions.

The specs have been written to use random input values.  While this approach is unconventional, it provides more convidence than would an attempt to test an effectively infinite number of edge cases<!-- ha!  Get it? -->.  Some specs do occasionally fail; the frequency at which this occurs is determined by the accuracy of the constants `HyperbolicCanvas.INFINITY` and `HyperbolicCanvas.ZERO`.

The Jasmine library itself has been modified to run each spec multiple times, and a random number seed is used so that errors may be reproduced.  The seed and the spec run count can be set in the options menu on the [SpecRunner][jasmine] page.

[jasmine]: https://ItsNickBarry.github.io/hyperbolic-canvas/jasmine/SpecRunner.html

### Browser Support

Certain browsers do not provide support for the hyperbolic trigonometric functions. Polyfills are available.

## Installation

### In-Browser

```html
<script type="application/javascript" src="dist/hyperbolic_canvas.js"></script>
```

### Via NPM

```
npm install --save hyperbolic-canvas
```

## Usage

Pass a unique selector of a div element, to the function `HyperbolicCanvas.create`.  Nonzero width and height styling must be specified.  Absolute px values in a 1:1 ratio are recommended:

```html
<div id="hyperbolic-canvas" style="width: 600px; height: 600px;"></div>
```

```javascript
let canvas = HyperbolicCanvas.create('#hyperbolic-canvas');
```

### API

See `API.md` for a list of functions and their descriptions.

---
_Source: https://npm.io/package/hyperbolic-canvas · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._