How to count the number of indices in a Gnuplot input file

Question

so I want to plot from a data file which has an undetermined number of fields of x and y data (of unknown but constant length). I want to plot them all together on one graph

Answer 1

If you have gnuplot >= 4.6.0, you can use the stats command:

#!/usr/bin/env gnuplot

reset

datafile = 'data.dat'

set terminal png size 600,400
set output 'test.png'

stats datafile

plot for [i=1:STATS_blocks] datafile index (i-1) pt 7 ps 2 title 'record '.i

If your data looks like this (with two blank lines separating the data blocks)

1 1


2 2


3 3


4 2


0 3

That script will make this plot:

The same should apply for blocks of data with more than one (x,y) pair.