[GRASS-user] how to overcome gaps in the roads network

GRASS GRASS user
1

Hi all,

Trying to use v.net.distance or v.net.iso on my network, I have found some gaps in it. Namely some roads are cut in the middle, thus distorting the results. I am looking for the easiest way (a function or so) to fix, overcome such problems/fixing the network, probably using a threshold or so.

I am aware of 2 hard solutions:

  1. fix it manually
  2. get a better layer of roads

However, since I’m working on the national scale the first one will take forever and the second is problematic due to data scarcity.

Best,

Dor

2

You can try v.edit tool=snap thresh=… The threshold will be in the units of the coordinate system, so probably meters. But you’ll have to be careful. THis might snap road ends that you don’t want to snap. (like any automated procedure). If, on the other hand, the gaps are small, this method might help. – Micha

···

Hi Dor
On 03/28/2013 03:56 PM, ãåø ôøéãîï wrote:

Hi all,

Trying to use v.net.distance or v.net.iso on my network, I have found some gaps in it. Namely some roads are cut in the middle, thus distorting the results. I am looking for the easiest way (a function or so) to fix, overcome such problems/fixing the network, probably using a threshold or so.

I am aware of 2 hard solutions:

  1. fix it manually
  2. get a better layer of roads

However, since I’m working on the national scale the first one will take forever and the second is problematic due to data scarcity.

Best,

Dor

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Micha Silver
GIS Consultant, Arava Development Co.
[http://www.surfaces.co.il](http://www.surfaces.co.il)
3

Thanks Micha.

I’ve tried it in the past, but it messed up the network. I believe that the gaps are too big (at least some of them), and I kind of hoped for a miracle. Anyway, I started again with OSM data, which I believe is better than what I have, though it need some processing.

Thanks again. If someone however have any idea of how to perform the miracle I was referring to (see my question above),feel free to write back

Best,

Dor

2013/3/28 Micha Silver <micha@arava.co.il>

Hi Dor

On 03/28/2013 03:56 PM, דור פרידמן wrote:

Hi all,

Trying to use v.net.distance or v.net.iso on my network, I have found some gaps in it. Namely some roads are cut in the middle, thus distorting the results. I am looking for the easiest way (a function or so) to fix, overcome such problems/fixing the network, probably using a threshold or so.

You can try v.edit tool=snap thresh=…
The threshold will be in the units of the coordinate system, so probably meters.
But you’ll have to be careful. THis might snap road ends that you don’t want to snap. (like any automated procedure). If, on the other hand, the gaps are small, this method might help.

Micha

I am aware of 2 hard solutions:

  1. fix it manually
  2. get a better layer of roads

However, since I’m working on the national scale the first one will take forever and the second is problematic due to data scarcity.

Best,

Dor

This mail was received via Mail-SeCure System.

_______________________________________________
grass-user mailing list
[grass-user@lists.osgeo.org](mailto:grass-user@lists.osgeo.org)
[http://lists.osgeo.org/mailman/listinfo/grass-user](http://lists.osgeo.org/mailman/listinfo/grass-user)

This mail was received via Mail-SeCure System.


-- 
Micha Silver
GIS Consultant, Arava Development Co.
[http://www.surfaces.co.il](http://www.surfaces.co.il)