[geos-devel] Porting LengthIndexedLine.project?

David Turner novalis at novalis.org
Mon Jul 27 17:42:17 EDT 2009

On Thu, 2009-07-23 at 21:53 +0200, strk wrote:
> On Thu, Jul 23, 2009 at 11:13:34AM -0400, David Turner wrote:
> > JTS has a class called LengthIndexedLine with a method "project", which
> > lets you figure out  the nearest point on a line to a given point.  This
> > is useful, for instance, if you are trying to figure out what street a
> > person is on from (possibly slightly inaccurate) GPS observations.
> > 
> > http://tsusiatsoftware.net/jts/javadoc/com/vividsolutions/jts/linearref/LengthIndexedLine.html#project(com.vividsolutions.jts.geom.Coordinate)
> > 
> > PostGIS calls this function st_line_locate_point.
> > 
> > GEOS doesn't seem to have it, even though I was under the impression
> > that GEOS was merely a port of JTS.  If I port JTS's project function
> > and related functions such as extractPoint to GEOS, would that patch be
> > likely to be accepted?  Or am I missing something about the relationship
> > between JTS and GEOS?
> Your patch would be welcome. Make sure to include unit testing please.

I have a patch.  Unfortunately, I do not yet have unit tests, because I
cannot find the relevant Java unit tests to port.  I could write my own,
but it seems like some of the other code uses ported Java unit tests,
and I want to follow the common practice.

Can you point me to the Java unit tests?

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