automationgnuplot

How to automatically replot a graph every few seconds in gnuplot?

I have a data file a.dat that is updated every few seconds. I wish to plot it in gnuplot every few seconds to see the changes

plot "a.dat"

What is the easiest way to do it? Thanks.

Solution

  • Make a script with a loop:

    while (1) {
    plot "a.dat"
    pause 1      # waiting time in seconds
}

    Execute it with gnuplot script.gp.

    For purposes of code structure and debugging, you might prefer the following alternative:

    plot "a.dat"

while (1) {
    replot
    pause 1
}

    This has the advantage that you do not have to put a complicated plot command inside the loop and do not suffer from incorrect line numbers for the plot command in error messages (that happen in at least some version of Gnuplot).

    Finally, if your Gnuplot is so old that it does not yet support loops, there is the alternative:

    plot "a.dat"

pause 1
reread

    With reread making the script interpreter jump to the beginning of the file again.