GNUPLOT is very easy tool to plot the data in nicer way! How to plot data from file ' data.dat ' for total row lets say 2000? --> Traditional way p " data.dat " u 1:2 w l or plot " data.dat " using 1:2 with line But, How to plot data for row from 1000 to 2000? --> p [1000:2000][] " data.dat " u 1:2 w l So far this is easy. Right? Now how to plot data for row from 1 to 1000 and 1001 to 2000? Hmm... Quit tricky. Lets do the following: [use some bash scripting ;-)] --> p "<(sed -n '1,1000p' data.dat )" u 1:2 w l, \ "<(sed -n '1001,2000p' data.dat )" u 1:2 w l Old New