Posts Tagged ‘auto-clustering’

MarkerClusterer in an All New Flavor – ActionScript! (GoogleGeoDev)

Friday, August 14th, 2009

[Editor's note: An AS3 Flash / Flex library for auto-clustering near map location markers into groups symbols. This speeds map rendering and groups points all within the same neighborhood, avoiding "red dot fever" marker overload. An AS3 implementation of existing JavaScript extension. Still needs to account for geographic region clustering (not just within a grid). Thanks Laris!]

Republished from Google Geo Developer Blog.
Monday, July 27, 200. 

My name is XIAO Juguang – just call me Juguang. I am a freelance software developer based in Beijing, China. Technically speaking, I’m double sided. On one side, I specialize in knowledge management and business modeling, traditionally using LAMP and now experimenting with offerings like Google App Engine. On the other side, I love visualization in time and space, with charts, trees, graphs, and maps, always using the power of ActionScript/Flex, with the help of open-source projects like Degrafa, Axiis, and Birdeye, and of course, APIs like the Google Maps API for Flash.

A few month ago, Xiaoxi Wu (also from China!) created the MarkerClusterer library for the Google Maps JavaScript API v2 and released it in their open source utility library. This library did automatic clustering of markers placed on a map, so that a large amount of markers wouldn’t overcrowd the map or overwhelm the user. This is a great technique for having a better performing map (see this talk for more tips on improving map performance), and the Flash map community immediately rushed to port the code to ActionScript. Developer Sean Toru posted the first port, a version that was only Flash-compatible, Ian Watkins modified that port to use Flex packages, and then I refactored the code to be more ActionScript-friendly and released it into the open-source library. It’s great when random strangers can collaborate together on a common code goal. :)

To see how the AS3 MarkerClusterer works, try out the demo (shown above). As you zoom and pan the map, you can witness how the markers are clustered and re-clustered. To learn how to use MarkerClusterer on your own map, view the source code of the demo. To use the library, check out the source code and import it into your project.

The current algorithm is quite simple, just clustering markers in a grid and using static images for the cluster markers. Future extensions could include support for regional clustering or using arbitrary DisplayObjects for the cluster markers. If you’re interested in extending the library, join the project.

New Feature: Cluster Your Map’s Markers (Click2Map)

Monday, November 3rd, 2008

[Editor's note: I learned about this technology from Click2Map for selecting markers in Google maps using a building tool and grouping them together as 1 marker at certain zoom levels. I'm not sure it is the best solution... but I like that the functionality is there. Seems like there should also be a more general solution for auto aggregation and disaggregation based on zoom level. I have seen this at a few sites, including Every Block. There is a tip on this a the ESRI mapping center for more GIS focused folks.]

All content below from Click2Map press release . . .

The team of Click2Map is proud to officially launch a feature that tackles one of the major weaknesses of online maps: Crowded maps.

The experience of maps is often diminished when markers are concentrated in a specific location, therefore lapping over one another. Here at Click2Map, as some of you already know, we are dedicated to take Google Maps to a higher level of control for your various professional needs.

Hence the auto-cluster feature! The auto-cluster feature is an easy-to-use tool of our map editor that will enable you to create a unique marker for each area where markers are too densely concentrated. Visitors can simply click on this unique marker to unveil the list of markers it withholds.

Movie Stars in Hollywood
View full page map

The clustering tool enables you to laser-tune the display of your clustered markers based on 3 parameters:
- Clustering rate: the higher the rate, the more markers will be cluttered
- Minimum markers: indicates the number of markers necessary to start building a cluster
- Maximum zoom: indicates from which level of zoom markers won’t be clustered anymore

The video below shows the new auto-clustering tool in action for the Hollywood celebrities’ map we created for the occasion.

To conclude, here is why the auto-clustering tool is a big deal for us:
1. It tackles the problem of markers overlap.
2. It becomes a new productivity tool for power-mapbuilders looking for the perfect map design.
3. It is so easy to apply that even first-time mapbuilders can figure it out on the fly.

Visit Click2Map