How to cut a hole by smooth circle?

[crest621010]

Dear all,
I want to cut a smooth circular hole in a 2D model, but I can only get the sharp edges. Could you help me with it?
The commands I used are as follows:

NEPER="neper --rcfile none"
$NEPER -T -n 100 -dim 2 -domain "square(200,200):translate(-100,-100)"
-transform "cut(cylinder(0.0,0.0,0,0,0,1,20))"
-o circle03
$NEPER -V circle03.tess -print circle03