[postgis-devel] Calculating flow direction

George Silva georger.silva at gmail.com
Fri Jul 30 13:05:48 PDT 2010


Oooo Pierre, that it is true. I forgot to look at that use case.

But, did you tested the function? I'm getting a few weird values for some
tests i've been running.

Can anyone else run some tests to it?

I have on the oven a fill sinks and a identify sinks function almost ready.
A more complicated one is accumulated flow, but it's coming.

Any suggestions on how I can achieve the use case that Pierre talked about?
Is it possible to union all rasters inside a single table?

Thanks,

George

On Fri, Jul 30, 2010 at 5:01 PM, Pierre Racine
<Pierre.Racine at sbf.ulaval.ca>wrote:

>  This is great George,
>
>
>
> I guess your function works only on a single raster. Would be nice if it
> would work on a tiled coverage. In this case you have to compute edge values
> by getting values from neighbour tiles. A bit (!!) more complicated.
>
>
>
> Pierre
>
>
>
>
>
> *From:* postgis-devel-bounces at postgis.refractions.net [mailto:
> postgis-devel-bounces at postgis.refractions.net] *On Behalf Of *George Silva
> *Sent:* 28 juillet 2010 21:48
> *To:* PostGIS Development Discussion
> *Subject:* [postgis-devel] Calculating flow direction
>
>
>
> Hello PostGIS developers,
>
> I just built a flow direction function for WKT Raster. I know it's not the
> most efficient, but looks like it works.
>
> I would like (if you have the time/interest) to test it and report
> inconsistent results.
>
> I'm working on function for identifying sinks, removing sinks and creating
> a accumulated flow raster.
>
> Your comments are most welcome. The function is the attachment.
>
> --
> George R. C. Silva
>
> Desenvolvimento em GIS
> http://blog.geoprocessamento.net
>
> _______________________________________________
> postgis-devel mailing list
> postgis-devel at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
>


-- 
George R. C. Silva

Desenvolvimento em GIS
http://blog.geoprocessamento.net
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