echo "-1 1 -1 1" \
 | unu reshape -s 2 2 \
 | unu resample -s 500 500 -k tent -c node -o x 

unu swap -a 0 1 -i x -o y

unu join -i x y -a 0 -incr \
 | unu project -a 0 -m l2 \
 | unu 2op - - 0.6 \
 | unu 2op spow - 0.3333333 \
 | unu resample -s x1 x1 -k bspln3ai -o tmp.nhdr

echo "space dimension: 2" >> tmp.nhdr
echo "space origin: (0,0)" >> tmp.nhdr
echo "space directions: (1,0) (0,1)" >> tmp.nhdr
echo "kinds: space space" >> tmp.nhdr

../bin/dnorm -i tmp.nhdr -o cbrt-500-unit.nrrd

rm -f x y tmp.nhdr tmp.raw