How to plot data without a separate file by specifying all points inside the Gnuplot script?

Question

My program generates bash scripts that call gnuplot. I don\'t want to have to make an extra file to store the data; is there any way I can explicitly call all of the values?

Answer 1

10 years later...

You can write something like this directly in gnuplot:

plot "< ./format.sh '{(1,5),(2,10),(3,1)}'"

where format.sh is a pretty simple script in a local file (remember to give it exec permissions):

#!/bin/bash
echo "$1" | sed 's:^..\(.*\)..$:\1:' | sed 's:),(:\n:g' | sed 's:,: :g'

How does it works?

The three sed commands do the following:

1. drops the first and last two characters, respectively {( and })
2. changes the sequence ),( to a newline
3. changes the remaining , to spaces

So:

$ ./format.sh '{(1,5),(2,10),(3,1)}'
1 5
2 10
3 1

The gnuplot plot "< command" syntax levers on popen to run command in a shell, capture the output and plot it on the fly. It can be pretty useful also in other circumstances.