[GRASS-user] grass : how to do Isochrone maps?

[Moritz Lennert]

On 07/12/14 23:38, image93 wrote:
> Hello,
>
> Thank you for your reply. Sorry i'm newbie with grass
>
> 1/ I downloaded grass 7 beta on my windows 7. I installed the v.isochrones
> from addons.
> But how to use this new extension ? is it possible to use an graphical
> interface (gui) or i have to use the prompt command?

Just type v.isochrones in the command console of the GUI (or in the 
terminal) and the graphical interface of the command will pop up.

If you want to include extensions in your menus, or just customise the 
existing menus, you can use the toolboxes [1].

>
> So according to you, it's more appropriate to use v.isochrones than
> v.net.iso ?

v.net.iso gives you isochrones along networks, so the different segments 
of the network will be categorised according to the isochrone they 
belong to. See the examples in the man page for illustration: [2] or a 
video (also illustrating the new interactive network tool) [3]

v.isochrones creates polygons across all the space of the current 
working region, i.e. it estimates travel time also for places that are 
not on the network. The man page does not seem to be online currently, 
but you can see a video based on a development version for illustration [4].

>
> 2/ Regarding my area of study : the region of Paris.

OpenStreetMap is of very good quality in Paris, so you can use that.

Moritz



[1] http://grass.osgeo.org/grass70/manuals/wxGUI.toolboxes.html
[2] http://grass.osgeo.org/grass70/manuals/v.net.iso.html
[3] https://www.youtube.com/watch?v=NRLK2RBw3tI
[4] http://tomahawk.ulb.ac.be/moritz/v_isochrones_demo.ogv