Red Dwarf is a heatmap visualization of GitHub repository stargazers.

Play with the live demo.

Red Dwarf uses the GitHub API to determine the locations of people who have starred a given repository. Then, using the Google Maps API, these locations are translated into geocoordinates and fed into a heatmap. The result is a beautiful and detailed visualization of global positions of a repository's stargazers.

Red Dwarf depends on Google Maps for geocoding and mapping. You must get a Google Maps API key to access these services.

Import the Google Maps JavaScript API. Appending libraries=visualization to the source path will ensure that you have the heatmap library available. Replace YOUR_KEY with the API key provided to you by Google.

<script src="http://maps.googleapis.com/maps/api/js?key=YOUR_KEY&sensor=false&libraries=visualization"></script>

Instantiate a new RedDwarf object, the constructor of which accepts a configuration object (see Settings).

var stars = new RedDwarf({
	user: config.user,
	repository: config.repository,
	map_id: config.map_id
});

• user (required) The GitHub user login of the repository owner.
• repository (required) The GitHub repository name.
• map_id (required) The ID of the HTML element in which to draw the map.
• cache_location The path (relative or absolute) of a JSON file containing precomputed geolocation data. If omitted, Red Dwarf will compute all data from scratch (see Performance). Note: this file's contents are equivalent to the output of the toJSON method.
• map_zoom The initial zoom level of the heatmap. Default: 2. (more info)
• map_lat The initial latitude position on which the heatmap is centered. Default: 20. (20 degrees north of the equator) (more info)
• map_lng The initial longitude position on which the heatmap is centered. Default: 0. (Prime Meridian) (more info)
• map_type The initial type of the heatmap: road, satellite, hybrid, or terrain. Default: "roadmap". (more info)

• toJSON Returns a JSON representation of a mapping of string locations to geocodes, the number of repository stars, and a mapping of stargazers' user logins to their respective user objects.

Red Dwarf will trigger each of the following events during processing. Arguments passed to the event handlers are listed below the event name (where applicable).

Event handlers are defined by including functions keyed by the respective event name in the settings object.

• onRepositoryLoaded Fired after successfully loading repository info from the GitHub API.
  • data The data object returned by GitHub.
• onRepositoryError Fired after unsuccessfully loading repository info from the GitHub API.
  • message The error message returned by GitHub.
• onCacheLoaded Fired after successfully loading the JSON cache file.
• onStargazersUpdated Fired after processing a chunk of at most 100 repository stargazers.
  • num_stargazers The number of stargazers processed so far.
• onStargazersLoaded Fired after successfully loading all stargazers.
• onLocationUpdated Fired after successfully loading a single stargazer's profile.
  • num_resolved_stargazers The number of stargazers whose profiles have been loaded so far.
  • num_stargazers The total number of profiles to load.
• onLocationLoaded Fired after successfully loading all stargazers' profiles.
• onPointsUpdated Fired after geocoding a chunk of at most 10 stargazer locations.
  • num_resolved_points The number of locations geocoded so far.
  • num_stargazers The total number of locations to geocode.
• onPointsLoaded Fired after successfully geocoding all locations and drawing the heatmap.

It's important to pre-cache the geolocation data because the Google Maps geocoding API places strict limits on the frequency of requests. Trial and error indicates that this limit is in the neighborhood of 40 requests per minute. This means a repository with 200 stars would take 5 minutes to get all geocoordinates. By default, Red Dwarf rate limits requests using a technique based on work by Nicholas Zakas.

Also note that repositories with many thousands of stargazers will likely hit usage limits on GitHub's API, because each stargazer's profile must be queried in order to get their location. Rate limiting is currently in development for this scenario.

For these reasons, it's best to pre-cache as frequently as possible. This will prevent each page load from incurring the usage limit penalizations.

Red Dwarf will only make API calls for data not already in the cache.

Red Dwarf uses publicly-available stargazer information including login names and locations via the GitHub API. Locations are only derived from stargazers who have opted in to making their location public in their GitHub profile.

Copyright (c) 2012 Rick Viscomi ([email protected])

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.