[GRASS-user] Network Analysis in GRASS

[Markus Metz]

On Tue, Oct 2, 2012 at 12:49 PM, Moritz Lennert
<mlennert at club.worldonline.be> wrote:
> On 02/10/12 11:37, Margherita Di Leo wrote:
>>
>>
>>
>> On Tue, Oct 2, 2012 at 11:35 AM, Moritz Lennert
>> <mlennert at club.worldonline.be <mailto:mlennert at club.worldonline.be>>
>> wrote:
>>
>>     On 01/10/12 10:10, Phil Donovan wrote:
>>
>>         Kiaora GRASS!
>>
>>         I require a network tool which can calculate 'service areas'. I
>> know
>>         GRASS can currently do this but the specific problem I have is
>>         that I
>>         need to do it for a very large dataset (400,000 locations). I
>> tried
>>         this with ArcGIS tool (sorry!) but it failed to 'solve' due to an
>>         overloaded memory. Would the GRASS tool 'v.net.iso' be able to
>>         process
>>         this without breaking?
>>
>>
>>     I don't have a straight answer to the question, but generally GRASS
>>     can handle fairly large datasets. It might depend more on the
>>     resources of your machine.
>>
>>     The best way to find out would be to try. ;-)
>>
>>
>> ..And please let us know :)
>
>
> Yes ! :-)
>
> As a follow-up: you might want to try grass7 as AFAIR some improvements in
> the modules only exist in that version for the moment. MarkusM can you
> confirm that ?

v.net.iso itself has not changed much, but vector network analysis for
large datasets (as other vector operations) should require much less
memory in GRASS 7 because of substantial vector library changes. I
have not tried network analysis with 400,000 locations myself (yet),
but in theory the module would either bail out quickly with an
out-of-memory error or happily crunch along.

Markus M
>
> Moritz