[GRASS-dev] Adding hexagonal rasters to GRASS

[Laurent C.]

Hello Luis,

I saw the video of the webinar of your colleague João P Leitão in
April about the hex version of the CADDIES model and I was asking
myself "is there any GIS software supporting hexagonal rasters?"
So I'm quite excited about the prospect of having support in GRASS ;)
However, I'm not sure if I can be of much help about the implementation.

Regards,
Laurent Courty


2017-07-23 10:50 GMT-05:00 Luí­s Moreira de Sousa <luis.de.sousa at protonmail.ch>:
> Dear friends,
>
> I presented hex-utils at the GISTAM conference in April, here is the video:
> https://www.youtube.com/watch?v=uLO4HDCVBp0
>
> This was before the QGis plug-in was completed, but for the rest it is
> pretty much the same story.
>
> Before the FOSS4G-E, in my mind the next phase of the project would be to
> code the abstraction functionalities in C++ (or C), to make it fully
> portable and easier to use with other languages, particularly Java. After
> that would then come a map algebra and spatial analysis.
>
> But as Luca said during the Q/A, it is probably better to start outright
> within GRASS. This will require the abstraction of the raster concept,
> together with operations like neighbourhood, number of neighbours, distance
> to neighbours, etc. With that done most of the raster modules would function
> the same way for squared and hexagonal rasters. Still, this would require a
> complete revision of all the raster modules.
>
> For a programmer, the main difference between hexagonal and squared rasters
> is the cell addressing system: with hexagons the axis are not orthogonal.
> However, it is possible to store an hexagonal raster in a bi-dimensional
> array like you would store a squared raster. I wrote an article last year
> with full details on the HexASCII file format and how to deal with hexagonal
> cell adressing, but it is still under review. I can not send it to the list,
> please send me a personal message if you wish to read it.
>
> It would be great if we can take this forward. I imagine it is a load of
> work, but it will make GRASS an even more awesome system ;)
>
> All the best.
>
> --
> Luís Moreira de Sousa
> Im Grund 6
> CH-8600 Dübendorf
> Switzerland
>
> Phone: +41 (0)79 812 62 65
> Email: luis.de.sousa at protonmail.ch
> URL: https://sites.google.com/site/luismoreiradesousa
>
>
>
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