[Geotools-gt2-users] newbie: Snap a Point to a Line problem with openstreetmap shape file

[Vittorio C. <vit...@gm...>]

Hi,

I am trying to develop some simple gps software in java to get more skills
with geotools and I found some big problem with the snap (gps coordinates)
to line (road) example.


http://svn.geotools.org/trunk/demo/example/src/main/java/org/geotools/demo/jts/SnapToLine.java

I am able to get the gps coordinates from usb gps and put them over a map,
but I can't work with the low accuracy of the gps data cause the position
is always outside the road path.

I tried to use SnapToLine.java with a openstreetmap shape
http://downloads.cloudmade.com/europe/southern_europe/italy/marche/marche.shapefiles.zip

i tried with the shp file without success.

In few words I need to transfrom my realtime gps data in snap to road gps
data, to correct the low accuracy and put the position in middle of the
road path.

So I would like to know if this way is right, and what kind of file shape
format I need to use shapetoline function.

Thanks a lot for your help

Vittorio