! Example of contour plot with colorized lines. ! Author: Francois Tonneau size 20 13 include contourplus.gle include palettes.gle set font ss begin contour data "volcano.z" values from 100 to 200 step 5 end contour sub hue z local adjusted = (z - 100) / (200 - 100) return viridis(adjusted) end sub amove 3 2.5 begin graph size 12 8.5 fullsize subticks off x2ticks off y2ticks off axis grid color #c0c0c0 labels color black hei 0.5 set lwidth 0.03 xaxis min 0 max 850 ! '850': see the top line of volcano.z yaxis min 0 max 600 ! '600': see the top line of volcano.z xtitle "Meters north" dist 0.6 hei 0.6 ytitle "Meters west" dist 0.6 hei 0.6 axis dticks 150 begin layer 1500 set lwidth 0.045 draw contourlines "volcano" "hue" end layer end graph amove 16 8.5 set hei 0.6 write "Altitude (m):" begin key absolute 16 8 just tl nobox dist 0.4 hei 0.5 for value = 100 to 200 step 20 line color hue(value) lwidth 0.04 text num$(value) next value end key