[GRASS-user] how to g.region

[Raffaello Brondi]

Hi Hamish.

> Raffaello Brondi wrote:
>   
>> i'm using GRASS 6.2 for developing a Web Processing Service.
>>     
>
> Have you seen Jachym's PyWPS?
>   http://pywps.wald.intevation.org
>   
yes i saw it..but unfortunately i have to develop the service using Java.
>   
>> One of the operations offered by the service takes two raster maps as 
>> inputs.
>> The raster map resulting from this operation would have different 
>> spatial extents based on the input maps: the result would have the 
>> extent equal to the extent of one of the two input maps, or equal to
>> the union of the extents of the two input maps or equal to the
>> intersection of the extents of the two raster maps.
>> In order to develop the service i need to manage these four cases by 
>> changing the GRASS region.
>> Supposing that the input rasters are "raster1" and "raster2", the 
>> possible configurations are:
>>
>>    1. region = raster1 --> g.region rast=raster1
>>    2. region = raster2 --> g.region rast=raster2
>>    3. region = the union of raster1 and raster2 --> g.region 
>> rast=raster1,raster2
>>    4. region = the intersection of raster1 and raster2 --> ?
>>
>>
>> As far as i see, using the g.region command, there is no way to specify 
>> the last point except to manually set the nord,sud,ovest and east 
>> values, but unfortunately i can not use this way.
>> Is there any other command in GRASS that i can use instead of g.region 
>> to set the current region as the intersection of two rasters?
>>     
>
>
> This is not very efficient, and more like 'g.region zoom=', but you could
> do:
>
> g.region rast=map1,map2
> r.mapcalc 'intersect= if(!isnull(map1) && !isnull(map2), 1, null())'
> g.region zoom=intersect
> g.remove intersect
>
>
> But probably Wolf's method is what you want.
>
>
> Hamis
This is the solution i need :).
thanx a lot!

Raffaello Brondi