xrange -4 4
xprange -2 2
yrange -4 4
yprange -2 2
xcollimator -3.162 3.162
# ycollimator -1e20 1e20 # no y collimator uses "large" limits
# baseres 10
iterations 10 100 1000 2000 5000
# Cell lattice follows
D 1
K 1
D 1
K -1 -0.2