code for sun/shadow exercise

> wall:=plot([[0,0],[0,2]],thickness=3,color=green):
sun1:=plottools[disk]([0,0],.2,color=yellow):
rays1:=j->[ (.5+.1*(-1)^j)*[cos(j/17*2*Pi),
sin(j/17*2*Pi)], .3*[cos(j/17*2*Pi), sin(j/17*2*Pi)]]:

> rays:=seq(plot(rays1(j)),j=1..17):

> sun:=plots[display]({sun1,rays},scaling=constrained):

> base:=plot([[-6,0],[4,0]],thickness=2,color=black):
dotline:=plot([[-5,4.5],[4,0]],linestyle=3,thickness=1):

> transun:=plottools[translate](sun,-6,5):

> plots[display]({transun,wall,base,dotline},axes=none);

>