size 9 6 include "contour.gle" set font texcmr begin letz data "saddle.z" z = 3/2*(cos(3/5*(y-1))+5/4)/(1+(((x-4)/3)^2)) x from 0 to 20 step 0.5 y from 0 to 20 step 0.5 end letz begin contour data "saddle.z" values 0.5 1 1.5 2 3 end contour begin graph scale 0.85 0.75 center title "Saddle Plot Contour Lines" hei 0.35 data "saddle-cdata.dat" xaxis min -0.75 max 11.75 yaxis min -1.5 max 21.5 d1 line color blue end graph contour_labels "saddle-clabels.dat" "fix 1"