[GRASS-dev] GSoC Proposal: Python package for topology tools

[Maris Nartiss]

Hello Facundo,
the easiest way would be moving functions of v.generalize into a
library (e.g. grass_generalize) and thus make available for calling
via ctypes.
In the past I have had a good success manipulating GRASS vectors via
ctypes. It takes more skill than a plain Python implementation but it
is easier than a full blown C code and faster than pure Python one.

Māris.

ceturtd., 2019. g. 28. marts, plkst. 03:13 — lietotājs Facundo Ferrin
(<facundo.ferrin at gmail.com>) rakstīja:
>
> Hi Luca!
>
> Thanks for replying! In my job, there were things we had to do programmatically. For example, to manipulate geometries that reach the backend from a GeoJSON we use tools like these:
>
> https://pcjericks.github.io/py-gdalogr-cookbook/geometry.html#create-geometry-from-wkt
>
> However, polygon simplification does not work very well because it does not take topology into account. My idea was to port part of the GRASS algorithms to be able to use them without needing the graphical interface or command line, but only importing a library in a Python script.
>
> Is it something that you have in mind to do or that might be useful to you?
>
>
> El jue., 28 de mar. de 2019 a la(s) 00:32, Luca Delucchi (lucadeluge at gmail.com) escribió:
>>
>> On Tue, 26 Mar 2019 at 03:11, Facundo Ferrin <facundo.ferrin at gmail.com> wrote:
>> >
>> > Hi there!
>>
>> Hi Facundo,
>> >
>> >
>> > My name is Facundo Ferrin. I am a nuclear engineer who is taking a master in Computer Vision in Barcelona, and finally I found my opportunity to contribute to OSGeo by applying two things that I really like: Python and Backend development . I do not know exactly what I should write in this first email, so I'll start by listing the projects I'm interested in.
>> >
>> > I'm working in a company that is developing a platform for precision agriculture called Auravant (https://www.auravant.com/). I work as a backend developer and data analyst and I use daily almost every tool that you post in the ideas: GeoServer, PostGIS, QGis. I'm also porting a tool for polygon simplification called topoJSON (https://github.com/fferrin/topojson).
>> >
>> > ---
>> > MY MAIN IDEA is to start porting GRASS tools into a python package that can be used in other projects (beyond the client to use by command line). I don't know if it's something you have in mind but for offline and automated analysis it would be very useful. I particularly had problems when I tried to simplify geometries since the geometry of polygons was not taken into account.
>> > ---
>>
>> Your idea is not clear to me, there are already two Python library to
>> work with GRASS. you can find some ideas in the proposal page
>> https://trac.osgeo.org/grass/wiki/GSoC/2019 (for example
>> Neweasy-to-useCLIandAPIforGRASSGIS) and
>> https://trac.osgeo.org/grass/wiki/GSoC/2018 (Improve GRASS integration
>> in QGIS 3)
>>
>> > Hope to hear from you soon!
>> >
>>
>> --
>> ciao
>> Luca
>>
>> www.lucadelu.org
>
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