plop is an incredibly simple GUI plotting program. It takes y-axis values from standard input, and displays them in a plot.

Install some dependencies:

sudo apt install -y libgtk-3-dev valac

Then compile the binary:

make

This will produce ./build/plop. You can move this into your path if you like.

Simply pipe numerical data into the plop command, where each line is a y-axis value. For example:

$ cat examples/sin.txt | ./build/plop

The plop command can also perform smoothing via an exponential moving average. For example, look at the plot of examples/noisy_exp.txt:

$ cat examples/noisy_exp.txt | ./build/plop

You can smooth this plot out using the --smooth option:

cat examples/noisy_exp.txt | ./build/plop --smooth 0.95