[GRASS-user] polar projection with grid lines

[Ken Mankoff]

Hi List,

I'm trying to set up a polar projection and draw some grid lines. I'm having trouble a) getting the grid lines to the pole and b) rotating it so a different longitude is the center longitude. I'm using the following code:

grass72 -e -c epsg:3413 ./tmp
grass72 ./tmp/PERMANENT

xy0=$(m.proj -i coordinates=0,40)  # set corners to 40° N
xy1=$(m.proj -i coordinates=180,40)
x0=$(echo ${xy0} | cut -d"|" -f1)
y0=$(echo ${xy0} | cut -d"|" -f2)
x1=$(echo ${xy1} | cut -d"|" -f1)
y1=$(echo ${xy1} | cut -d"|" -f2)

g.region s=${y0} n=${y1} w=${x1} e=${x0}

d.mon start=wx0
d.erase
d.grid -w size=10:0


The d.grid manual suggests calling 2x near the poles, but even doing that (e.g. d.grid -w size=1 direction=east-west) does not improve where the grid lines are drawn. Also, if I wanted Russia, not Greenland, pointing "down" on the map, how do I rotate this projection?

Thanks,

  -k.