aUCBLogo Demos and Tests / drawcoil

to drawcoil
   hideTurtle
   WindowMode
   N=20
   Nstart=6
   Nend=N
   drawcoil1
   Nend=N-1/4
   drawcoil2
end

to drawcoil1
   clearScreen
   PenUp
   imax=10000
   istart=imax*Nstart/N
   iend=imax*Nend/N
   Ra=300
   setPenSize 300/2/N
   i=istart
   goto_point
   setX xCor-3
   fillCircle 4
   goto_point
   PenDown
   for [i istart iend]
   [   goto_point
   ]
   setXY Ra Ra-10
   fillCircle 6
   updateGraph
   setSaveSize [400 300]
   saveScreen "C:/temp/drawcoil1.png
end

to goto_point
   R=Ra*i/imax
   phi=360*N*i/imax
   setXY R*cos phi R*sin phi
end

to drawcoil2
   clearScreen
   PenUp
   imax=10000
   istart=imax*Nstart/N
   iend=imax*Nend/N
   Ra=300
   setPenSize 300/2/N
   i=istart
   goto_point2
   setX xCor+3
   fillCircle 4
   goto_point2
   PenDown
   for [i istart iend]
   [   goto_point2
   ]
   setXY -Ra+30 Ra-10
   fillCircle 6
   updateGraph
   saveScreen "C:/temp/drawcoil2.png
end

to goto_point2
   R=Ra*i/imax
   phi=360*N*i/imax
   setXY -R*cos phi -R*sin phi
end