On Fri, 28 Oct 2011, toke wrote:
I think that I might have found a bug in spgrass6 or I might be doing
something wrong. When I call v.distance within R it seems to calculate but
it do not update the column of interest.
Im using the the following software:
platform x86_64-pc-linux-gnu 10.10
language R
version.string R version 2.13.2 (2011-09-30)
Here are my script
R
#calling library
library(spgrass6)
# checking GRASS setup
gmeta6()
output:
gisdbase /home/toke/Desktop/PHD/databehandling/artikel_3/gis/grassdb
location mapset
mapset aalborg
rows 1200
columns 1100
north 6328400
south 6316400
west 551800
east 562800
nsres 10
ewres 10
projection +proj=utm +no_defs +zone=32 +a=6378137 +rf=298.257222101
+to_meter=1
# reading spatial files from GRASS database
recrea_h <-readVECT6("recrea_h")
area_b1 <-readVECT6("area_b1")
execGRASS("v.distance", flags=c("overwrite"), from="recrea_h", to="area_b1",
from_type="centroid", to_type="area", dmax=as.integer(1),
+ upload="to_attr", column="area_b1", to_column="value")
100%
100%
84 categories - no nearest feature found
235 categories read from the map
235 categories exist in the table
235 categories read from the map exist in the table
235 records updated
v.distance complete.
The column is not updated even though it seems that it is actually are
calculating.
The same calculation in GRASS works.
Please show your exact GRASS command line - otherwise we can only conclude
that you are asking for different things. You are asking for a maximum
distance of integer 1 metres here, so you should look carefully at the 84
categories - no nearest feature found message - did that also appear in
the output from running the command directly in GRASS?
Roger
Cheers Toke
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Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
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