Et effektivt værktøj til at lave tematiske kort på Google Maps ...
A very nifty tool for the creation of thematic maps on Google Maps ...
The GMapCreator is a freeware application designed to make thematic mapping using Google Maps simpler. The application takes a shapefile containing geographic areas linked with attributes and automatically generates a working Google Maps website from the data. It does this by pre-creating all the necessary files and saving them into a directory. Publishing the map on the web is then just a matter of copying files onto a web server, allowing Google Maps to be used with the majority of ISPs.Download version 1.31 now (released 27 May 2008)
The following is an example produced using the application:
The data above shows an aggregate of carbon monoxide data collected over a two week period during May 2004 using GPS tracked sensors. In order to produce this map, the sensor logs were converted into a shapefile and loaded into the Google Map Creator. This data forms the worked example installed with the application and the steps required to do this are detailed in the example.
To date, a variety of thematic map for different parts of the world have been produced to test the viability of the application with real data on production web servers. The links below point to some of these test maps.
|1998 Global GDP (data from the world bank)||Dan Vickers' Output Area Classification [more info]|
|(962 files 5.12MB)||(98,018 files 438MB)|
|eSociety classification [more info]||Remoteness index of Newfoundland and Labrador, Canada|
|(993 files 6.89MB)||(370 files 1.86MB)|
How It Works
The main problem with creating Google Maps sites in this way is that the number of tiles can be very large. The application manages this problem by allowing the user to control the maximum level of zoom and the extents of the geographic area. For example, with a map of worldwide Gross Domestic Product by country, there is no point in zooming in beyond the point where one country fills the whole screen, so the maximum level of zoom is limited and the number of tiles kept within a manageable level. In this example, six zoom levels are adequate for the data, resulting in 962 files occupying 5MB on the disk. At the other end of the scale is data from a GPS tracked carbon monoxide sensor used within a 1KM grid square in London. In this case, the maximum zoom level is used to show the 5 metre data grid, but only 71 files (less than 1MB) were created as the geographic area is so limited.
A more complicated example showing an animation of a GPS tracked CO sensor can be found at: www.casa.ucl.ac.uk/bbc/dontdieyoung/log_25-09-2006_154206.html.
Source: UCL Centre for Advanced Spatial Analysis
Read more: http://www.casa.ucl.ac.uk/software/gmapcreator.asp