Question: Exporting an array plot to an eps file

I am trying to save an array plot to an eps file. My code is the following:

restart: with(plots): currentdir("G:/"): plotsetup(default):
alpha := [.2, .25, .3, .35, .4]:
beta := -0.1e-1:mygamma := -1:delta := 0.1e-1:start := 0:finish := 20:

for i to 5 do
 eqn1 := diff(x(t), t)-x(t)*(alpha[i]-beta*y(t));
 eqn2 := diff(y(t), t)-y(t)*(mygamma-delta*x(t));
 
 solt[i] := dsolve([eqn1 = 0, eqn2 = 0, x(start) = 80, y(start) = 40], [x(t), y(t)], numeric, method = rkf45, range = start .. finish);

 xplot[i] := odeplot(solt[i], [t, x(t)], t = start .. finish):
 yplot[i] := odeplot(solt[i], [t, y(t)], t = start .. finish):
end do:

rplot := array(1 .. 2):
rplot[1] := display([xplot[1], xplot[2], xplot[3], xplot[4]]):
rplot[2] := display([yplot[1], yplot[2], yplot[3], yplot[4]]):

plotsetup(ps, plotoutput = `myplot.eps`, plotoptions = `portrait,noborder`):
display(rplot)

I expect the plotsetup command to change the output device to the file myplot.eps but it does not work. Answer of DSkoog in

http://www.mapleprimes.com/questions/121011-Export-Whole-Array-Plot-To-GIF-JPEG#comment121071

works without problem.