Dear list,
I want to compute a cost surface using r.cost. I used the GRASS user interface to input the parameters which resulted in the following line:
r.cost input=costTotal output=costsurface coordinate=-10698,-7021 stop_coordinate=-1216,-221 max_cost=0 percent_memory=25.
I didn't use the -k option as this needs longer execution time and I ame only testing at the moment, but my proces is already running for over 1000 minutes. Is this normal (image dimensions: 640x480)? If so how can I estimate the remaining execution time? If not: what's going wrong?
Greetz,
Ellen
Oeps, it seems like the default maximal cost given in the GUI is 0??? This might be the problem. I ame rerunning the line below without the max_cost=0 (stupid me...). Hope this will solve the problem.... it is now running for 4 minutes, so I let you know if it is actually solved somewhere later today, tomorrow...?
Ellen
Ellen De Beuckeleer wrote:
Dear list,
I want to compute a cost surface using r.cost. I used the GRASS user interface to input the parameters which resulted in the following line:
r.cost input=costTotal output=costsurface coordinate=-10698,-7021 stop_coordinate=-1216,-221 max_cost=0 percent_memory=25.
I didn't use the -k option as this needs longer execution time and I ame only testing at the moment, but my proces is already running for over 1000 minutes. Is this normal (image dimensions: 640x480)? If so how can I estimate the remaining execution time? If not: what's going wrong?
Greetz,
Ellen
Hi all,
the problem is not solved. My r.cost is still running :(.
Any suggestions?
Ellen
Ellen De Beuckeleer wrote:
Oeps, it seems like the default maximal cost given in the GUI is 0??? This might be the problem. I ame rerunning the line below without the max_cost=0 (stupid me...). Hope this will solve the problem.... it is now running for 4 minutes, so I let you know if it is actually solved somewhere later today, tomorrow...?
Ellen
Ellen De Beuckeleer wrote:
Dear list,
I want to compute a cost surface using r.cost. I used the GRASS user interface to input the parameters which resulted in the following line:
r.cost input=costTotal output=costsurface coordinate=-10698,-7021 stop_coordinate=-1216,-221 max_cost=0 percent_memory=25.
I didn't use the -k option as this needs longer execution time and I ame only testing at the moment, but my proces is already running for over 1000 minutes. Is this normal (image dimensions: 640x480)? If so how can I estimate the remaining execution time? If not: what's going wrong?
Greetz,
Ellen
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3500 Hasselt
tel: +32 (0)11 45 20 16
fax: +32 (0)11 45 20 17
www.incgeo.be
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Ellen De Beuckeleer wrote:
the problem is not solved. My r.cost is still running :(.
Any suggestions?
r.cost performs extremely badly on large maps where only a fraction is
held in memory. Reducing the region resolution or increasing the
percent_memory= option will get around this.
If the region is actually 640x480, you should have no trouble with
percent_memory=100.
--
Glynn Clements <glynn@gclements.plus.com>
thanx for replying. I tryed to run the r.cost on a smaller map and with percent_memory=100. Moreover, I did run it with the -v option. It still has the problem of getting stuck in the "finding cost path" part (the percentage still raises above 100%). If I do the exact same thing in via the GUI, the green status bar first fills up slowely and once filled completely it starts again and again and again... but then it fills a lot faster. I never get an output map. Can this be because there is something wrong with my command line?
my region is now:
projection: 0 (x,y)
zone: 0
north: -5864
south: -6085
west: -9543
east: -9365
nsres: 1
ewres: 1
rows: 221
cols: 178
I used start coordinates: -9533, -6023 for my last run
Ellen
Glynn Clements wrote:
Ellen De Beuckeleer wrote:
the problem is not solved. My r.cost is still running :(.
Any suggestions?
r.cost performs extremely badly on large maps where only a fraction is
held in memory. Reducing the region resolution or increasing the
percent_memory= option will get around this.
If the region is actually 640x480, you should have no trouble with
percent_memory=100.
--
------------------------------------------------------
IncGEO
Kempische steenweg 297 bus 2
3500 Hasselt
tel: +32 (0)11 45 20 16
fax: +32 (0)11 45 20 17
www.incgeo.be
------------------------------------------------------
PROBLEM SOLVED! my stupid newbe mistake 
My cost layer contained some negative values. That's why the r.cost got into an infinite loop. I hope that by writing this here another newbe might not loose so much time...
Ellen De Beuckeleer wrote:
thanx for replying. I tryed to run the r.cost on a smaller map and with percent_memory=100. Moreover, I did run it with the -v option. It still has the problem of getting stuck in the "finding cost path" part (the percentage still raises above 100%). If I do the exact same thing in via the GUI, the green status bar first fills up slowely and once filled completely it starts again and again and again... but then it fills a lot faster. I never get an output map. Can this be because there is something wrong with my command line?
my region is now:
projection: 0 (x,y)
zone: 0
north: -5864
south: -6085
west: -9543
east: -9365
nsres: 1
ewres: 1
rows: 221
cols: 178
I used start coordinates: -9533, -6023 for my last run
Ellen
Glynn Clements wrote:
Ellen De Beuckeleer wrote:
the problem is not solved. My r.cost is still running :(.
Any suggestions?
r.cost performs extremely badly on large maps where only a fraction is
held in memory. Reducing the region resolution or increasing the
percent_memory= option will get around this.
If the region is actually 640x480, you should have no trouble with
percent_memory=100.