[GRASS-user] problems with r.cost

hello,

i'm a very new user to grass and am using r.cost in grass6.2. i'm trying
to run a cost analysis on my raster and having some difficulty. when
running, it seems that the function will start to run fine, but then when
looking at top it will pause for 10-15 minutes before continuing, while
there is one processor completely free, or both pretty much free. this
will continue to happen, where it seems r.cost will run for a period of
5-10 minutes, then pause for 10-15 before continuing again. i've tried
running on different memory percentages, but this doesn't seem to have any
effect. has anyone seen this before?

while running in verbose, it outputs a lot of statements:

segment_seek: invalid argument

and a few GRASS_INFO_WARNINGs with various numbers.

when the file is finally completed, it seems as if there are only three
"strips" of the file that were run and then rotated and moved to the top of
the output image, and the rest of the output seems to be garbage. the
command i'm running is:

r.cost -v -k input=grass_watermask_30mbuffer output=cost_for_point_8
start_points=point_8 max_cost=0 percent_memory=8 --overwrite

where the start_points file point_8 is a one point vector file.

this might be a simple problem, and if so, i appreciate any help.

thanks,

paul

Paul Haverkamp wrote:

i'm a very new user to grass and am using r.cost in grass6.2. i'm
trying to run a cost analysis on my raster and having some difficulty.

which version of 6.2? 6.2.0 or 6.2.1?

how big is your region? (g.region -p) Does it happen if you make the
region smaller or adjust the resolution?

can you reproduce it using the Spearfish demo dataset? if so, can you
post instructions with that in the grass bug tracker?

thanks,
Hamish