gnuplot xyz x has a cluster
xxxxxxxxxx
set palette maxcolors 10
set palette defined ("0" "black", "1" "red", "2" "green", "3" "blue", "4" "yellow", "5" "cyan", "6" "magenta", "7" "orange", "8" "violet", "9" "dark-red" )
plot 'plot_gnu_data.dat' using ($1*20/1000000):2:3 with points pointtype 6 pointsize 0.2 lc palette notitle
set ylabel "RMSD {\305}"
set xlabel "Time {/Symbol m}s"
pause -1
### end of code
data looks like this
time concentration cluster
1 0.5 1
2 0.6 1
3 0.7 2
4 0.6 3
color change happen according to 3rd column,
change number of colours according to number of clusters