% --- end of displayed preamble in the book ---
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
numeric u; u=5mm;
pickup pencircle scaled 1pt;
for i:=0 step 10 until 360:
draw ((i/360)*10u,3u*sind(i));
endfor;
pickup pencircle scaled .5;
endfig;
end;
