[GRASS-user] How to assign costs to nodes using v.net.distance

[דור פרידמן]

Hello all,

After I've got my v.net.distance up and running I have to adjust my
analysis method to the software's capabilities. Basically, I have a 3
layered network: myroads_net2 which contain layers as follow:

Layer 1: Arch (roads)
Layer 2: Points (Landfills - destinations)
Layer 3: Points (Settlements - source)

As one might understood I'm trying to calculate the lowest cost route
between each settlement (layer 3) to each landfill (layer 2). Roads' costs
are constant, which now set to 1 (currency per distance unit - I guess that
it is meter). I would like to include a cost for landfill (gate fee) which
will be measured with the same currency. MY attempt to use ncolumn (cost
for nodes) didn't go well. I have opened a new column (double precision) in
layer 2 and named it gatefee. I have assigned 0 to all cats, except cat=3
which I have assigned with 60. My expectation was that at least some of the
settlements that were allocated to cat=3 on layer 2 will be allocated to
another one. However after running v.net.distance again with
ncolumn=gatefee I have found out that more settlements were allocated to
cat=3 of layer 2.

Did I misused that option? I can't find any guide to how to use it in the
manual or tutorials and will appreciate an explanation or a reference to
such guide or tutorial.

Best,

Dor
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20130328/848a0bc7/attachment.html>