Just a simple question (I imagine) but, lets say I have the following data file:
# no x data, it's sampled for instance each second. 23 42 48 49 89 33 39 44 97 How (if possible) can I plot that as if it were
1 23 42 48 2 49 89 33 3 39 44 97 using the 1,2,3,.. (first column) as x ?
doing something like: plot "file.dat" using (lineNumber):3 for instance.
If you don't want to rely on awk, gnuplot can do this as well. See help plot datafile using and help plot datafile using pseudocolumns. Try:
plot "file.dat" using (column(0)):3 
plot "file.dat" using 0:3
plot "file.dat" using 3
E.g. to plot the third line of the datafile:
plot "DATAFILE" u 3 or with awk:
plot "<awk '{print FNR,$0}' DATAFILE" u 1:4 Note that awk adds linenumbers, so the first column is linenumber.
does the same, gnuplot is automatically using the line-number for the x-axis
Or more simply, you can also type: plot "file.dat" u ($0):3
This will allow you to modify the index variable linearly, as you would any other column
Such as scaling by 2 and adding 1: plot "file.dat" u (($0)*2+1):3
