Say you have a series of plots called plot1.ps, plot2.ps, ...
plot99.ps in a directory and you would like to convert them into a
single animated GIF file in this order, because you really can't
figure how to understand what's going on in them otherwise. Let's
rename them first so they'll be properly ordered:

for (( i=1; i<=9; i++ )); do mv plot$i.ps plot0$i.ps; done

and then let convert turn them into an animated GIF with 1s per frame
in one go. The -alpha off command removes any transparency.

convert -delay 100 -loop 0 plot*.ps -alpha off plot_animated.gif