I always thought /drawdot wasn't meant to draw perfect circle, kind of, because i guess I only ever used small size, but there is a bug when size is below 7:

Code
//window -pdf @test -1 -1 1000 500 | var %x 15,%y 15,%n 1 | while (%n <= 50) { drawdot -r @test 255 %n %x %y | inc %n | inc %x 60 }
below 7, circles are not draw correctly.

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