About LUGmap

Linux User Groups around the world

The maps are generated using the worldmap package. The resulting set of vectors is converted to PNG and annotated with LUG positions using the PNG library GD.pm.

Distances from the clickpoint to LUGs are calculated as a great circle distance.

This is in part a demonstration for geotags, though currently the LUG entry form does not actually fetch Web pages and parse geo tags, but relies on submitted values. It does, however, use the same elements, and is expected to be updated to monitor Web pages on a regular basis.

Updates and Reloads

In order to reduce load on the server (currently a Pentium Pro), and to enable efficient use of browser and public cache, both blank and annotated PNGs are cached on the server after conversion from vector format. The missing-document script is modified to recreate missing PNGs.

After a new LUG is added, the cached PNGs are currently not automatically updated. However, a subsequent map query (zoom, center, info) will update the server cached image. A reload (shift-reload) may then be necessary to update browser and public cache before the new LUG is visible on the screen.

Bookmarks and Links

Do not bookmark or link to arbitrary views of the map; the bookmarked link will refer to a server cached image which may not always be updated when the LUG list is updated.

If there is demand, links specifically for bookmarking may be added to the views.