Re: [Geotools-gt2-users] Interpolating from contour lines

[Diego J. <die...@gm...>]

By all means ;)

I'll try the TPS and IWD then :)
I'm using maven in my project (for geotools 8.0-M2) and I added the 
dependencies in the listed in the following link to my pom.xml:

http://code.google.com/p/jgrasstools/source/browse/extras/examples/jgt-dev-example/pom.xml

However:

Missing artifact org.jgrasstools:jgt-jgrassgears:jar:0.7.2:compile

And a whole lot more, including missing artifacts from geotools 8.0-M1. 
In my pom.xml I'm already declaring 8.0-M2 dependencies.
How should I configure it?

> ------------------------------------------------------------------------
>
> 	Michael Bedward <mailto:mic...@gm...>
> October 13, 2011 11:09 AM
>
>
> Mmm... sounds tasty. Are you saying that Kriging is inferior to thin
> plate splines generally, or is it likely to be data dependent ?
>
> As an aside: I have vector to raster utilities on my todo list for
> jaitools - the aim being to generalize the existing GeoTools code into
> a jaitools module and then bring that back to GeoTools in a geospatial
> wrapper as aaime did for the raster to vector code. If Jan's
> interpolation code was available, and subject to permissions, licences
> etc., it would be fantastic to have this as part of the jaitools
> module. Perhaps then jgrasstools could depend on that too ?
>
> (Sorry for hijacking your thread Diego)
>
> Michael
> ------------------------------------------------------------------------
>
> 	andrea antonello <mailto:and...@gm...>
> October 13, 2011 10:51 AM
>
>
> Hi Michael,
>
>> Another good link which I should have mentioned before is the
>> JGrassTools project which is run by one of the GeoTools developers. It
>> includes a kriging algorithm written to use GeoTools classes:
>>
>> http://code.google.com/p/jgrasstools/source/browse/hortonmachine/src/main/java/org/jgrasstools/hortonmachine/modules/statistics/kriging/Kriging.java
>>
>> I'm cc-ing this message to the author who is a font of wisdom on all
>> things to do with landscape modelling.
>
> lol, that was a good one. Where should I make the downpayment? :)
>
>> A post about the approach you end up using would be much appreciated - thanks.
>
> I would not use the Kriging for lanscape interpolation.
> Some time ago I started to port the Interpolation methods created by
> Jan Jezek (Thin Plate Spline and IWD) to jgrasstools by adding in it
> quadtree support. They are working quite well, but I stopped in the
> middle of the testing phase and never touched them again.
> In fact I promised Jan I would get back to him like 3 months ago
> (sorry Jan, work drawned me), since I wanted to should him how great
> his work would look like in OMS :)
> I would use those, if I had to choose. In that case right now you
> would need to extract the points from the lines and give them an
> elevation attribute. You would also pass a gridgeometry and it would
> interpolate in the grid points.
> Tada!
> Well, you noticed: would, would, would.
> I am currently promising a lot of stuff around, so I will go on. I
> could bring those tools in official experimental jgrasstools land if
> Jan agrees and nobody blames me. :)
>
> Cheers,
> Andrea
>
>
>
>
>> Michael
>>
> ------------------------------------------------------------------------
>
> 	Michael Bedward <mailto:mic...@gm...>
> October 13, 2011 10:41 AM
>
>
>
> Another good link which I should have mentioned before is the
> JGrassTools project which is run by one of the GeoTools developers. It
> includes a kriging algorithm written to use GeoTools classes:
>
> http://code.google.com/p/jgrasstools/source/browse/hortonmachine/src/main/java/org/jgrasstools/hortonmachine/modules/statistics/kriging/Kriging.java
>
> I'm cc-ing this message to the author who is a font of wisdom on all
> things to do with landscape modelling.
>
> A post about the approach you end up using would be much appreciated - 
> thanks.
>
> Michael
> ------------------------------------------------------------------------
>
> 	Diego Jesus <mailto:die...@gm...>
> October 13, 2011 10:11 AM
>
>
> Thanks for your reply.
>
> Sorry, you're right I should have provided more information.
>
> The contour lines are MultiLineStrings. For the output raster I would 
> need proper interpolation. I guess I'll have to implement it myself 
> then, or use one of the solutions in the link you gave me.
>
> I'll post here my solution.
>
>
> ------------------------------------------------------------------------
>
> 	Michael Bedward <mailto:mic...@gm...>
> October 13, 2011 12:38 AM
>
>
>
> Ah grasshopper ! A couple of hours is merely the blink of an eye on
> the cosmic timescale of the average open source programming task...
>
> You need to provide more information so that people here can help you.
> On the input side: are your contour lines either LineString objects
> are something that can be turned into LineStrings ? On the output
> side: were you wanting proper interpolation of values between contours
> for the output raster or would simple filling the regions between
> contours with a uniform value be ok ? For true interpolation you
> would usually use an algorithm such as Kriging which GeoTools does not
> provide.
>
> Also, take a look at this message in the list archives...
>
> http://osgeo-org.1803224.n2.nabble.com/How-can-I-convert-mid-mif-map-to-matrix-of-big-cells-with-average-territory-information-tp1943037p1943037.html
>
> While it is not exactly the same use case that you have it might give
> you some ideas or help you get started.
>
> Michael