Spatial Functions

[Jonathan mayer <jo...@yahoo.com.INVALID>]

 Hi All,
Over the last few days, I have started to develop new calcite spatial functions based upon locationtech libraries - jts-core and proj4j - basically replacing the esri-geometry-api.

JTS is the Gold Standard and there are far more examples/templates out there from an algo implementation perspective.
It is still early days yet - lots to do - but I have placed a project on GitHub - jonrmayer/geofunctions - which contains all the code to date.

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jonrmayer/geofunctions

Contribute to jonrmayer/geofunctions development by creating an account on GitHub.
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 It is intended to be a like-for-like replacement of the existing calcite-core/runtime/GeoFunctions.java file.
With some minor edits to calcite-master pom /calcite-core pom - it is feasible to drop this in as a replacement - adding the calcite imports etc to the top of the file.
Tests however will be a problem - eg. spatial.iq will no longer be relevant. ESRI outputs geometries to JSON whereas JTS outputs WKT - this will need to be rewritten.
My current plan is to focus on implementing as many functions as possible with basic tests and then to improve on the (very) basic Maven testing before letting anyone know that I am reasonably happy.
I should imagine that spatial.iq will have to wait a fair while - I will need it to test Geometry Collections for eg ST_DWithin/ST_Collect etc and hope that the maven test are enough from a confidence perspective.
A bit of background:- I have 10+ years in the GIS/spatial arena but only 1.5 years with Java ( very junior ) I know PostGIS/H2GIS/Oracle/SQlServer/OGR/NTS etc. - biased towards the former. I know what I am looking for re: results. My recent focus has been developing Spatial Data Flows within Apache Nifi - hence the interest in Calcite.
I would like to contribute to the project but I don't believe that I could ever become a "Contributor" - I would mess it up.

I can build Calcite within my very narrow (Nifi) world view but do struggle with a full build. I need the help of a master if there is an appetite to integrate this.
I think I have managed to extend the current spatial function coverage - I have added a "Status Report" to the project - jonrmayer/geofunctions. I copied this from Calcite Documentation and it is a bit of a shorthand. I have removed/replaced/added various funtions but it provides a good overview.

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jonrmayer/geofunctions

Contribute to jonrmayer/geofunctions development by creating an account on GitHub.
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Regards,
Jonathan Mayer

Re: Spatial Functions

[Julian Hyde <jh...@apache.org>]

Sounds like an interesting project. I would be open to this replacing the current set of functions based on ESRI, if the quality and performance were superior.

As a database guy, and in particular an optimizer guy, I am very interested in recognizing certain patterns and rewriting them to use indexes (or similar). I hope that your implementation allows those kind of optimizations, just as the ESRI-based functions do.

Also I would love to get to full coverage of the SQL simple feature support, including a good test suite.

Can you please log a JIRA case to track the work that you are doing? Even if your work is outside of Calcite’s repo.

I looked at https://github.com/jonrmayer/geofunctions <https://github.com/jonrmayer/geofunctions> briefly. Did you decide on a license? If you are using Apache License, add LICENSE and NOTICE files, and add a license section to your pom.xml.

Julian


> On Dec 28, 2018, at 3:10 AM, Jonathan mayer <jo...@yahoo.com.INVALID> wrote:
> 
> Hi All,
> Over the last few days, I have started to develop new calcite spatial functions based upon locationtech libraries - jts-core and proj4j - basically replacing the esri-geometry-api.
> 
> JTS is the Gold Standard and there are far more examples/templates out there from an algo implementation perspective.
> It is still early days yet - lots to do - but I have placed a project on GitHub - jonrmayer/geofunctions - which contains all the code to date.
> 
> | 
> | 
> | 
> |  |  |
> 
> |
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> |
> | 
> |  | 
> jonrmayer/geofunctions
> 
> Contribute to jonrmayer/geofunctions development by creating an account on GitHub.
> |
> 
> |
> 
> |
> 
> 
> 
> It is intended to be a like-for-like replacement of the existing calcite-core/runtime/GeoFunctions.java file.
> With some minor edits to calcite-master pom /calcite-core pom - it is feasible to drop this in as a replacement - adding the calcite imports etc to the top of the file.
> Tests however will be a problem - eg. spatial.iq will no longer be relevant. ESRI outputs geometries to JSON whereas JTS outputs WKT - this will need to be rewritten.
> My current plan is to focus on implementing as many functions as possible with basic tests and then to improve on the (very) basic Maven testing before letting anyone know that I am reasonably happy.
> I should imagine that spatial.iq will have to wait a fair while - I will need it to test Geometry Collections for eg ST_DWithin/ST_Collect etc and hope that the maven test are enough from a confidence perspective.
> A bit of background:- I have 10+ years in the GIS/spatial arena but only 1.5 years with Java ( very junior ) I know PostGIS/H2GIS/Oracle/SQlServer/OGR/NTS etc. - biased towards the former. I know what I am looking for re: results. My recent focus has been developing Spatial Data Flows within Apache Nifi - hence the interest in Calcite.
> I would like to contribute to the project but I don't believe that I could ever become a "Contributor" - I would mess it up.
> 
> I can build Calcite within my very narrow (Nifi) world view but do struggle with a full build. I need the help of a master if there is an appetite to integrate this.
> I think I have managed to extend the current spatial function coverage - I have added a "Status Report" to the project - jonrmayer/geofunctions. I copied this from Calcite Documentation and it is a bit of a shorthand. I have removed/replaced/added various funtions but it provides a good overview.
> 
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> jonrmayer/geofunctions
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> Contribute to jonrmayer/geofunctions development by creating an account on GitHub.
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> Regards,
> Jonathan Mayer
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