https://github.com/laem/async-cartogram

Javascript non-blocking cartograms (web workers / node)
https://github.com/laem/async-cartogram

Last synced: 18 days ago
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Javascript non-blocking cartograms (web workers / node)

• Host: GitHub
• URL: https://github.com/laem/async-cartogram
• Owner: laem
• License: mit
• Created: 2015-06-22T09:55:14.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-06-25T08:45:50.000Z (over 9 years ago)
• Last Synced: 2024-08-09T13:16:57.017Z (3 months ago)
• Language: JavaScript
• Homepage: https://laem.github.io/async-cartogram/
• Size: 2.26 MB
• Stars: 24
• Watchers: 7
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
What ?

-----------

A **js cartogram library** that does not block the browser, using **web workers**, forked from the original [d3 cartogram](http://prag.ma/code/d3-cartogram/). It can also be run with **node**, which is nice for preprocessing geometries offline.

- Designed to handle a series of cartograms (called tasks) : compute all the maps at once then display them smoothly.

- Using only a geo subset of d3 (you'll probably use d3 again to display the map in the browser, add colors, transitions, hovers...).

- Also attempts to add the effective range tip from Algorithms for Cartogram Animation,

by Ouyang et al., hopefully making it slightly faster.

Usage :

--------

The library is compiled in `dist/` as [UMD](https://github.com/umdjs/umd), and has been tested using `require("dist/async-cartogram.js")`

```js

var promiseOfGeometries = AsyncCartogram(

  {

    topology: topojsonData,

    // geometries to reshape:

    geometries: topojsonData.objects.OBJECTNAME.geometries,

    projection: {

      name: 'mercator',

      translation: [X,Y],

      scaling: scalingFactor, //e.g. 2000

      center: [long, lat]

    }

  },

  values, // { taskId => { geoJsonFeatureValue => newArea} }

  featureProperty // geoJsonFeatureIdKey to link geojson features to values

);

```

See the [example](https://github.com/laem/async-cartogram/tree/master/example) app (cartogram of Paris) for detailed usage.

![L'escargot](https://raw.githubusercontent.com/laem/async-cartogram/master/example/capture.png)

Check the project for which this lib was created, [a 90-years cartogram of europe](https://github.com/laem/eurpop).