% beautiful00.mp % L. Nobre G. % 2014 prologues := 1; beginfig(1); numeric u, firstep, cylray, plangle, i, a, as, speed, dist, accel, li, aux; pair poi, tip, ref; pen one; accel = 0.27; u = 1.2cm; firstep = 6u; cylray = 2u; plangle = 12; as = 5; ahangle := 30; ahlength := 0.035cylray; one = pencircle scaled 0.015cylray; drawoptions( withpen one ); li = 3; aux = li*accel*firstep*(li+1); fill (-cylray,0)--(aux,0)--(aux,-ahlength)--(-cylray,-ahlength)--cycle withcolor 0.5white; for i=0 upto li: speed := i*accel; ref := (speed*firstep*i,0); for a=as-90 step as until 270-as: poi := ref+cylray*(dir(a)+up); dist := abs( poi-ref ); tip := poi+speed*dist*dir(0.5*a-45); drawarrow poi--tip; endfor; endfor; picture tmpicture; tmpicture = currentpicture; currentpicture := nullpicture; draw tmpicture rotated -plangle; endfig; end.