# set terminal svg size 600,400 dynamic enhanced font 'arial,10' mousing name "discrete_2" butt dashlength 1.0 
# set output 'discrete.2.svg'
set contour base
set cntrparam levels 3
set cntrparam levels discrete 0,15 ,75 
set style data lines
set title "3 discrete contours at 0 15 & 75" 
NO_ANIMATION = 1
splot x*y