# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'concave_hull.1.png'
set border 3 front lt black linewidth 1.000 dashtype solid
set key invert samplen 4 spacing 1 width 0 height 0
set view  equal xyz
set samples 170, 170
set size ratio -1 1,1
set style data lines
set xtics border in scale 1,0.5 nomirror norotate  autojustify
set xtics  rangelimit 0.5 
set ytics border in scale 1,0.5 nomirror norotate  autojustify
set ytics  rangelimit 0.5 
set ztics  rangelimit 0.5 
set cbtics border in scale 1,0.5 nomirror norotate  autojustify
set cbtics  rangelimit 0.5 
set rtics  rangelimit 0.5 
set title "Concave hulls" 
set title  offset character 0, -2, 0 font ":Bold" textcolor lt -1 norotate
set xrange [ -0.500000 : 2.50000 ] noreverse
set yrange [ -0.500000 : 2.00000 ] noreverse
NO_ANIMATION = 1
N = 17
## Last datafile plotted: "$DATA"
plot $DATA using 1:2 convexhull with lines lw 2 lt 4 title "convex",      $DATA using 1:2 concavehull with lines lc "blue" title "concave",      $DATA using 1:2 with points pt 7 ps 2 lc bgnd notitle,      $DATA using 1:2:(sprintf("%d",int($0))) with labels font ",9" notitle,      keyentry title sprintf("chi_length = %.2f",GPVAL_CHI_LENGTH) noenhanced