v.net connection operation

[matmar]

Hi all,

I'm not able to connect points with the nearest line segment in a line vector using v.net.

v.net connects a line vector with the points in a point vector file. The connection process follows the category progress so the output is not the fittest solution for a network distance analysis as the one I need to perform.

Following, the commands to reproduce the issue in nc_spm_08_grass7:

g.region vect=roadsmajor
v.mkgrid map=points_grid -p position=region grid=20,20
v.net input=roadsmajor points=points_grid out=roads_to_points operation=connect threshold=5000 --o

plot:

d.mon wx0
d.vect roads_to_points
d.vect points_grid col=red display=cat

Is there a way to connect each point to the nearest original road segment?

Matteo

[matmar]

example of v.net op=connection output

[mlennert]

Replying to matmar:

Hi all,

I'm not able to connect points with the nearest line segment in a line vector using v.net.

v.net connects a line vector with the points in a point vector file. The connection process follows the category progress so the output is not the fittest solution for a network distance analysis as the one I need to perform.

Following, the commands to reproduce the issue in nc_spm_08_grass7:

g.region vect=roadsmajor
v.mkgrid map=points_grid -p position=region grid=20,20
v.net input=roadsmajor points=points_grid out=roads_to_points operation=connect threshold=5000 --o

plot:

d.mon wx0
d.vect roads_to_points
d.vect points_grid col=red display=cat

Is there a way to connect each point to the nearest original road segment?

Use the '-s' flag (Snap points to network) available in grass7.

Moritz

[matmar]

Replying to mlennert:

Replying to matmar:

Hi all,

I'm not able to connect points with the nearest line segment in a line vector using v.net.

v.net connects a line vector with the points in a point vector file. The connection process follows the category progress so the output is not the fittest solution for a network distance analysis as the one I need to perform.

Following, the commands to reproduce the issue in nc_spm_08_grass7:

g.region vect=roadsmajor
v.mkgrid map=points_grid -p position=region grid=20,20
v.net input=roadsmajor points=points_grid out=roads_to_points operation=connect threshold=5000 --o

plot:

d.mon wx0
d.vect roads_to_points
d.vect points_grid col=red display=cat

Is there a way to connect each point to the nearest original road segment?

Use the '-s' flag (Snap points to network) available in grass7.

Moritz

Hi Moritz,

-s glues points to the nearest network segment but doesn't connect each point to the nearest network segment (so I lose information). I attached a drawing about what I meant, hoping it helps.

[mmetz]

Replying to matmar:

Hi all,

I'm not able to connect points with the nearest line segment in a line vector using v.net.

v.net connects a line vector with the points in a point vector file. The connection process follows the category progress so the output is not the fittest solution for a network distance analysis as the one I need to perform.

This is a bug in v.net, fixed in r62683,4 (trunk, relbr7).

[mlennert]

As this has been fixed a year ago and there have been no complaints since, I'm closing this bug.