I have used the JTS linear referencing stuff before (and backed it onto oracle). I think the JTS stuff is only useful if you are storing additional measurements (in the form of additional doubles) along with your coordinates. I know that I could only store additional doubles in an Oracle SDO_GEOMETRY for example. If you are working with objects or strings then you best try something else.
It is also worth pointing out that there are several approaches to smearing additional data along your linestrings. The obvious one mentioned above is to record additional measurements associated with each point - you will occasionally create additional points just to capture measurement change (and will need to be careful that JTS does not simplify your data away as not required). And example is a straight section of road over which the speed limit changes (because there is a school). The Geometry would like to be a single straight line; but you will need to break out line segments to reflect the speed changes. The other approach is to store measurements in a "look aside" data structure - often by making use of percentages. So your string straight line is handled by a JTS as it likes; but you record three road speed measurements ( 50km from 0%-35%, 15km from 35%-51%, and 50km from 51%-100%). Sigh - all of this is great fun (and the kind of thing we do for a living at Refractions when we are not working on GeoTools). Cheers, Jody PS. When you evaluate the two approaches keep in mind the cost up a) updating the geometry (you will need to map the measurements over) b) updating the measurements > Hi, > >> Bryce wrote: "I presume you would like to build linear referencing >> functionality on top of the 19107 geometric objects." >> >> Not quite. I want to build linear referencing on top of JTS, but if I >> can do it in a way that will allow for the use of other geometry >> libraries I'm open to that. I need a LinearGeometry interface for this >> even if I'm just using JTS, so I might as well try to accomodate. >> >> > > Sorry if Im omitting something, but ... JTS linear referencing stuff is > not worthy for your requeriments? > > This approach allows you to reduce the problem to data model conversion > between libraries (JTS and the rest of libraries you need to use). > > Best regards! > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
