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% rmnbob.mp
% L. Nobre G.
% probably before 2004
input featpost3Dplus2D;
Spread := 70;
f := (5,7,10);
beginfig(1);
numeric i, r[], stepr, len, Numr, Minn, Maxn;
numeric fws, NumLines, linex;
path aro[], oneline;
color centre, axe, baseone, basetwo;
stepr := 0.1;
len := 3;
Numr := 5;
Minn := 5;
centre := (0,0,0);
axe := (1,0,0);
fws := 2;
NumLines := 30;
for i=0 upto NumLines:
linex := fws*(i/NumLines-0.5);
oneline := rp((linex,0.5*fws,-0.5*fws))
--rp((linex,-0.5*fws,-0.5*fws))
--rp((linex,-0.5*fws,0.5*fws));
draw oneline withcolor (0.7*background);
endfor;
baseone := centre+0.5*len*axe;
basetwo := centre-0.5*len*axe;
Maxn := Minn+Numr;
for i=Minn upto Maxn:
r[i] := i*stepr;
aro[i] := rigorouscircle(baseone,axe,r[i]);
endfor;
rigorousdisc( 0, true, baseone, r[Maxn], -len*axe );
drawoptions( dashed evenly );
rigorousdisc( 0, true, baseone, r[Minn], -len*axe );
for i=Maxn downto Minn:
filldraw aro[i] withcolor ((0.5+0.3*normaldeviate)*background);
endfor;
drawoptions( );
draw aro[Maxn];
endfig;
end.
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