Re: [Jaspa-users] Questions

[Simon G. <si...@sp...>]

Carlos,
>> OK, look I have been working on exposing JTS in Oracle's JVM now for quite a while. I am doing it more directly looking a functionality
>> that complements or fills gaps in the Oracle stack rather than any theoretically complete OGC/SFS compliant API. The results of my work
>> are documented on my website under what is called the GEOPROCESS PL/SQL package. I have actually renamed this to JTS and added
>> in a lot more functionality. It is ready to go up on my site to replace GEOPROCESS but it may not happen till next week. Still, GEOPROCESS
>> gives you a feel for what I have done.
> Thats good to know Simon, I think Marta already learned things from your blog about oracle. Im gonna meet her maybe tomorrow or Friday to see her work. She already told me though that at the beginning she started with Oracle 10.2 and java >1.4 but she changed to oracle 11 because she had problems with Jaspa, probably because java 1.5

Looking at Jaspa and its dependence on JTS I can see that there are really very few uses of Java 1.5 in its code that could not be easily converted back to 1.4.
This may not optimal for the future, but I still have lots of customers still on 10gR2 (all my Java/JTS code/packaging works fine on 10gR2 and 11gR2). Also,
this is a bit moot until JTS finally moves away from 1.4.

>> What are your plans for circular arc and geodetic support given that JTS doesn't support either?
>>
>  Geodetic support is very attractive research for me, specially because my mayor is Engineering in Geodesy and Cartography but before trying to implement Geodetic support in a serious way Jaspa must implement a tolerance system, as cluster in >ArcGIS. Unfortunately PostGIS does not implement a tolerance system either  and its incredible!!
>
> I think Martin Davis is working in geodetic support in JTS but JTS does not support tolerance system either.

Geodetic is very important. Currently I tell people to project to something planar, do the work, then project back. It would be nice not to have to do this.
My Geodesy knowledge (three years at Uni ending up with Geodesy III which was about the math keeping satellites in the sky!) is now 30 years old. I might
have gotten High Distinctions for all three years but I can't remember diddly squat. So, over to you!

>
>> (Aside: How is it that PostGIS etc all seem to use JTS/GEOS but from that basis extend to support circular arcs etc but don't work to help JTS/GEOS get that support?)
> The support of  PostGIS with curve geometries is very limited. In fact, if you wanna use the main spatial functionality you have to convert from and to curve geometries. It does not make sense for me.In  my opinion PostGIS project should have funded a lot the JTS project because the JTS project is the PostGIS Core.

It has been limited for quite a while. Oracle's support is not all that good but it appears a little better than the others. SQL Server Spatial Denali, from a cursory look, looks pretty good.
> The only other changes I needed to make (for 1.4 compliance as JTS is 1.4 compliant) were to change things like List<Geometry> ... to List and add in casts when needed. This was actually very simple to do as JASPA
> doesn't seem to use LinkedHashMaps etc with key/value typing. The only pain is:
>
>    public static <U> U[] removeNulls(U array[]) {
I would prefer to keep going with Oracle 11 and not change the Jaspa code about using java 1.4. I remember that I changed many methods with parametric types as List. e. g.: List <Geometry> list = ...

The latter List<Geometry> aren't a problem. (Pity Java doesn't have conditional compilation.) It is things like above that I don't understand how to code in 1.4. Also, LinkedHashMap<String,Geometry>
cannot be easily implemented in 1.4.
> I would be happy to change the code for you in agreed areas but only once the Oracle integration has occurred. Also, I am happy to offer to test Marta's work if you are interested.Perhaps once Marta is finished I could be involved as the maintainer of this branch of the code? But isn't one thing about JASPA to offer an alternate type system to Oracle (BTW
> aggregates with Java in Oracle are awful!) My needs are for a solution that is about integration.
>
> Happy to keep talking or get involved in any way you are comfortable with.
We are happy too you can get involved in the Jaspa project. When Marta finishes her work (I think soon), we will send it to you and we will keep talking about that.
Marta is going to start working in a company  so probably no one is going to maintain the Oracle branch code, so you are very welcome.

OK. Let's see what happens when we get there.

I will talk to Marta about testing her project too.

Again, OK. Happy help.

regards
Simon
-- 
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