[GRASS-user] v.what.rast for lines

[Achim Kisseler]

Hi Jitu,

a way would be to convert the lines to raster (v.to.rast) and calculate
the statistics (r.stats).

As every line has a unique id, the "raster-lines" will have.

Hope it helps,
Achim

Jitendra Kumar schrieb:
> Hi,
> "v.what.rast" allows to extract the values from the raster at the vector
> points. How to do a similar operation for a vector map consisting of
> lines instead of points. I have road network as vector and I wish to
> extract the average value over each line segment from a raster.
> 
> I thought of several options but had one or other conceptual problem. I
> can convert the vector line to points using "v.to.points" and extract
> the values at each point using "v.what.rast". But I am not sure how to
> identify the points lying on a particular line in order calculate the
> average over the line.
> I do want to preserve the lines in my road network vector data since it
> gets used in some other network analysis as well.
> 
> If I have several attributes associated with my raster, how to specify
> the attribute to be extracted to "v.what.rast" ?
> 
> I am quite confused as to how to do this. Any pointers would be of great
> help?
> 
> Thanks,
> Jitu
> 
> 
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