[postgis-devel] Feb. Code Sprint and WKTRaster?

[David Zwarg]

Hi Pierre,

ST_MapAlgebra is right down my alley!  It will be challenging to write the
parser, but I am already familiar with the MapAlgebra operations, and I
think that'll give me a good head start.

I will think about the specifications, and bounce them off you guys.  Should
I document the process on the wiki, or is this list the best place for that?

Thanks,
Zwarg

On Wed, Feb 3, 2010 at 10:15 AM, Pierre Racine
<Pierre.Racine at sbf.ulaval.ca>wrote:

>  David,
>
>
>
> You could also give a look at “ST_MapAlgebra(raster|geometry,
> [raster|geometry,...], ‘mathematical expression’, ‘raster’ |’geometry’) ->
> raster/geometry” which is a part of Objective B03c in the planning.
>
>
>
> This is a very interesting and complex function common to every serious
> raster GIS package. This is function is very independent from any other
> development and so can be work on in a isolated way. We must first write the
> specifications, agree on them and implement it. It implies writing an
> expression parser which is not an easy task. Basically the function returns
> a raster with values being the result of a mathematical expression applied
> on the values of one, two or many overlayed input rasters. We must then be
> very imaginative and see how we can apply the same behavior using one, two
> or many geometry. We could discuss that later.
>
>
>
> If we get a satisfying implementation, we could release it before WKT
> Raster 0.3.
>
>
>
> Pierre
>
>
>
> *From:* postgis-devel-bounces at postgis.refractions.net [mailto:
> postgis-devel-bounces at postgis.refractions.net] *On Behalf Of *Pierre
> Racine
> *Sent:* 1 février 2010 09:29
> *To:* PostGIS Development Discussion
> *Subject:* Re: [postgis-devel] Feb. Code Sprint and WKTRaster?
>
>
>
> Hi David,
>
>
>
> Unfortunalety there will be no representant of the WKT Raster team in New
> York at the end of february. We all save our money to meet at the next
> FOSS4G in Barcelona next fall: http://2010.foss4g.org/
>
>
>
> In terms of development, what would be very usefull now, would be to build
> further regression tests for WKT Raster. I’m not a specialist of regression
> test but there are some example in the \test\regress folder and Mateusz
> could certainly help you.
>
>
>
> You could also  work on objective B03a - Being able to set all the
> properties of a raster. This implies writing the specification and
> implementing the code.
>
>
>
> The planning page is not really up to date now. I have to work on it.
>
>
>
> Pierre
>
>
>
> *From:* postgis-devel-bounces at postgis.refractions.net [mailto:
> postgis-devel-bounces at postgis.refractions.net] *On Behalf Of *David Zwarg
> *Sent:* 18 janvier 2010 22:01
> *To:* postgis-devel at postgis.refractions.net
> *Subject:* [postgis-devel] Feb. Code Sprint and WKTRaster?
>
>
>
> Greetings,
>
> I will be participating in the OSGeo code sprint in February, and I would
> really like to help with the WKTRaster project in PostGIS.
>
> Where should I start to get up to speed with this project?  Will any other
> WKTRaster developers be at the code sprint?
>
> Thanks,
> David Zwarg
>
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> http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
>
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