Question

I am drawing multiple graphs via a shell script in gnuplot.
The graphs are drawn correctly, but am not am able to zoom in . Does any variable need to be set?
Here is the code:

---   for loop of script starts---
    gnuplot -persist <<EOF
            set term x11 1
            set title "IP : $ip Upstream capacity:$UP_CAP kbps"
            plot 'trace-0-dir1.txt' using (\$1-$min1):(\$2-\$1-$mindelay1) with lp
            set term x11 2
            set title "IP: $ip Downstream capacity:$DOWN_CAP kbps"
            plot 'trace-0-dir2.txt' using (\$1-$min2):(\$2-\$1-$mindelay2) with lp

    EOF
   ---for loop ends---

Answer 1

Once you switch away from the “x11 1” window the zooming is disabled. To regain control, you should switch back to the specific window (set term x11 1). Another issue is the x11 terminal. You should use wxt which can keep windows alive.

You can solve your issue by using the wxt terminal and separating the two plot commands, therefore not switching away from the window:

---   for loop of script starts---
gnuplot -persist <<EOF
set term wxt
set title "first"
plot x
EOF
gnuplot -persist <<EOF
set term wxt
set title "second"
plot x**2
EOF
---for loop ends---

With this, you have two zoomable windows open and you can still use your shell variables.

In general, you do not have to have console open in order to have active windows, just an appropriate terminal. Especially, the command

gnuplot --persist -e 'plot[0:10] sqrt(x)'

produces scrollable and zoomable windows if used with wxt. Try

gnuplot --persist -e 'set term wxt; plot[0:10] sqrt(x)'

Hope this helps.