Gnuplot plot specific lines from data file

Question

I have a data file with 24 lines and 3 columns. How can I plot only the data from specific lines, e.g. 3,7,9,14,18,21? Now I use the following command

plot 'xy.dat' using 0:2:3:xticlabels(1) with boxerrorbars ls 2

which plots all 24 lines.

I tried the every command but couldn't figure out a way that works.

Answer 1

Untested, but something like this

plot "<(sed -n -e 3p -e 7p -e 9p xy.dat)" using ...

Another option may be to annotate your datafile, if as it seems, it contains multiple datasets. Let's say you created your datafile like this:

1 2 3
2 1 3 # SetA
2 7 3 # SetB
2 2 1 # SetA SetB SetC

Then if you wanted just SetA you would use this sed command in the plot statement

sed -ne '/SetA/s/#.*//p' xy.dat
2 1 3
2 2 1

That says..."in general, don't print anything (-n), but, if you do see a line containing SetA, delete the hash sign and everything after it and print the line".

or if you wanted SetB, you would use

sed -ne '/SetB/s/#.*//p' xy.dat
2 7 3
2 2 1

or if you wanted the whole data file, but stripped of our comments

sed -e 's/#.*//' xy.dat

If you wanted SetB and SetC, use

sed -ne '/Set[BC]/s/#.*//p' xy.dat
2 7 3 
2 2 1