[GRASS-user] r.stream.basins error

[Francesco Mirabella]

Hi,
more detailes are these,  I can not reproduce it on speafish,

Grass 6.4 rc6 compiled on debian testing
The dem is the srtm 90 m dem, cut on an area of 12064631712 Square 
meters (1206463 hectars).
The region was set to the dem raster, I provided a minimum flow 
accumulation of 100 to get a "reasonable" river network.
Hope this can help

Francesco

Jasiewicz Jarosław wrote:
>  W dniu 12.10.2010 09:49, Francesco Mirabella pisze:
>> Hi,
>> thanks for you message,
>> the modules were compiled from the add-ons about one week ago, I 
>> suppose they should be the updated version.
>> What do you mean by "unique streams"? If you mean the number of 
>> streams which come out from the operation, these are about 7500. Do 
>> you think is the area too large? BTW I was successful with r.watershed 
>> on the same dataset but I just wanted to test these new modules
>>
>> Francesco
>>
>>
>>
>> Jarek Jasiewicz wrote:
>>> Francesco Mirabella pisze:
>>>> Hi all,
>>>> I am trying to generate a basins map from a dem using r.stream.basins
>>>>
>>>> I first cut the dem to the area I want to work on than run g.region 
>>>> to set the region to this map.
>>>> Then I calculated streams and streams flow directions with 
>>>> r.stream.extract.
>>>>
>>>> In order to get stream basins I used r.stream.basins:
>>>> r.stream.basins  dir=rivers_flow    stream=rivers   
>>>> basins=basins_rivers
>>>>
>>>> The output gives an error saying:
>>>>
>>>> Reading maps...
>>>> Calculate basins using streams...
>>>> Finding nodes...
>>>> ERROR: Stream and direction maps probably do not match
>>>> (Mon Oct 11 11:15:28 2010) Comando terminato (0 sec
>>>
>>>>
>>>> Why do they not match if I derived them with the same command and 
>>>> from the same dem ? Am I doing something wrong ?
>>> such errors appears when region dir map and stream map comes from 
>>> different operations. Try if you are using most actual 
>>> r.stream.extract and r.stream basins modules.
>>> How much unique streams you have created with r.stream.extract?
>>>>
>>>> thanks in advance
>>>> Francesco
>>>> _______________________________________________
>>>> grass-user mailing list
>>>> grass-user at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/grass-user
>>>
>>
> GRASS 6 or 7?
> 
> This error appears when the number of possible outlets overcome the 
> allocated memory for given raster. Memory is allocated as a sum of 
> vertical and horizontal resolution times 2. If the number of possible 
> outlets overcomes that values the error is throwing. In most standard 
> network this allocation is enough and is stored as a bug-handler to 
> avoid crashes or infinite loops if user will use maps from different 
> sources.
> 
> If you have a 7500 streams and you have raster map grater than 2000x2000 
> cells it should not happen. If not I have a problem.
> 
> For future use:
> 
> if you find any problem with continuosly developed software (like these 
> in add-ons) first:
> 
> - give us more information about version, of your GRASS and add-on
> - try to reproduce this error on standard GRASS dataset like SPEARFISH 
> or NC
> if error canot be reproduced:
> - give us more information of data type you are using: resolution, 
> region etc.


-- 
____________________________________________

Francesco Mirabella,
Geologia Strutturale e Geofisica
Universita' di Perugia,
Dipartimento di Scienze della Terra,
Piazza Universita' 1, 06100 Perugia (Italy)
tel: ++39.(0)75.584.7948
fax: ++39.(0)75.585.2603
skype: francesco.mirabella
web: http://www.unipg.it/~mirabell/
____________________________________________