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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