I'm working on a 15*10 km area, splatted in a 50*50 m cell grid. I want to compute the time needed to travel from a single starting point to each cell centroid, combining driving and walking time.
Using pgrouting,I already have the shortest time to every node of my paths (roads and hiking trails, with different speeds)
I computed the shortest path of each centroid to the nearest trail/road. Assuming the same node-centroid walking speed (4 km/h), I get a time for each. I had first used the "Walking time" extension on those segments, but some times weren't realistic (canyons).
But the time costs limits are raw on the raster: the nearest node isn't necessarily the fastest.
Beside that, this approach doesn't take into account the slope, I tried r.walk and r.drain, but I can't figure out how to use it with all this : there are over 4 000 roads/trails nodes and 27 000 centroids !
How can I get the least-cost path from any of the centroid to the fastest trail/road node ?
Thanks for your help. I'm using Qgis and Grass.
أكثر...
Using pgrouting,I already have the shortest time to every node of my paths (roads and hiking trails, with different speeds)
I computed the shortest path of each centroid to the nearest trail/road. Assuming the same node-centroid walking speed (4 km/h), I get a time for each. I had first used the "Walking time" extension on those segments, but some times weren't realistic (canyons).
But the time costs limits are raw on the raster: the nearest node isn't necessarily the fastest.
Beside that, this approach doesn't take into account the slope, I tried r.walk and r.drain, but I can't figure out how to use it with all this : there are over 4 000 roads/trails nodes and 27 000 centroids !
How can I get the least-cost path from any of the centroid to the fastest trail/road node ?
Thanks for your help. I'm using Qgis and Grass.
أكثر...