parabola  p 7 0 0 1 0.2
trim p p -1 1
copy p pr
2dtranslate pr 0 -4
reverse pr
convert result pr
2dpl 
2dpl
2dpu
2dpu
checklength result -l 3.3514748622014476
checkview -display result -2d v2d -path ${imagedir}/${test_image}.png