[GRASS-user] Re: Drivetime Isochrones

[Moritz Lennert]

[You seem to have gotten beyond some of your troubles, but just for the 
record, some answers.]

On 20/06/11 05:50, RKiTect wrote:
> Thanks for your help...
>
> unfortunately i am using the GUI and i must have an input for the 'nodes'
> section.

Which module are you speaking about ? Neither v.net nor v.net.iso have a 
'nodes' parameter.

> my centre layer doesn't show up for inputting into this... so i
> think my point file requires some sort of pre-processing, but not sure...

You have to connect your points to the streets using v.net. By default 
this will add the points as nodes to the street network and these nodes 
will have category values in layer 2. v.net.iso will by default look for 
these category values in layer 2, so you normally don't have to worry 
about the layers.

>
> if you try running the gui tool you will see what i mean... inputs required
> for arcs and nodes, but a standard grass pointfile does not show up in nodes
> dropdown box...

What do you mean by "standard grass pointfile" ? Your points have to be 
a vector layer. So, if you have them as an ascii file in the classic 
grass point format, you have to import it with v.in.ascii first.

Moritz