#1462: r.walk not working in Lambert Conformal Conic projection
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Reporter: cmbarton | Owner: grass-dev@…
Type: defect | Status: new
Priority: critical | Milestone: 6.4.2
Component: Raster | Version: svn-releasebranch64
Keywords: r.walk | Platform: Unspecified
Cpu: Unspecified |
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r.walk seems to be ignoring topography in a Lambert projection. r.cost
works fine. I'm attaching screen shots of an SRTM DEM of central Europe,
the results of r.walk on that DEM (with a friction map of 1), and r.cost
run on a slope map of the DEM from the same start point as r.walk.
#1462: r.walk not working in Lambert Conformal Conic projection
-------------------------+--------------------------------------------------
Reporter: cmbarton | Owner: grass-dev@…
Type: defect | Status: new
Priority: critical | Milestone: 6.4.2
Component: Raster | Version: svn-releasebranch64
Keywords: r.walk | Platform: Unspecified
Cpu: Unspecified |
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Comment(by cmbarton):
Markus,
Turns out my map is in Lambert Equal Area. My student's map is in Lambert
Conformal Conic and gives the same result. A geotif of the DEM is 3.9 MB,
which far exceeds the 256 Kb limit of the bug tracker. However, the world
file for r.out.tif is
#1462: r.walk not working in Lambert Conformal Conic projection
-------------------------+--------------------------------------------------
Reporter: cmbarton | Owner: grass-dev@…
Type: defect | Status: new
Priority: critical | Milestone: 6.4.2
Component: Raster | Version: svn-releasebranch64
Keywords: r.walk | Platform: Unspecified
Cpu: Unspecified |
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Comment(by mmetz):
From the dev ml, Oct 11 2011, Claudine Gravel Miguel:
"I think I've found what I thought it wasn't working. I reran the whole
thing on both UTM and conical and when looking at a big region, it seemed
like it wasn't working, but as soon as I zoom the window on the 'center'
point and I recalibrate the colors of the r-walk output, then the paths
appear to be fine, on both locations. I also ran the whole thing in both
6.4.2 and 7 and both works fine. I wonder if the problem you had is the
same, Michael, or if it was different.
I think that te reason why I thought the circle around the center point
was wrong is because I was comparing it to r.walk in lat long, which was
following very closely the results found in r.cost (following the
valleys), which, I know realize, were the wrong type of outcome.
So, I guess my part of the problem is resolved. Thanks for your help!"