gnuplot

You can run gnuplot interactively and it will open up a window containing your plot. Use the menu bar in the plot window to export to png or other formats.

Example usage:

$ gnuplot

# Let gnuplot choose the range for you.
gnuplot> plot sin(x)

# Specify the range.
gnuplot> plot [-pi:pi] sin(x)

# Can also specify the range on the y-axis.
gnuplot> plot [-pi:pi] [-0.5:0.5] sin(x)

# Plot multiple functions at once.
gnuplot> plot [-2:2] x, x**2, x**3

# Make a scatter plot from some data (comma- or space-separated).
gnuplot> plot "data.txt"

Links:

• gnuplot homepage
• https://www.manning.com/books/gnuplot-in-action-second-edition — can read this online.
• https://www.cs.hmc.edu/~vrable/gnuplot/using-gnuplot.html
• do a linear fit
• https://mathblog.com/getting-started-with-gnuplot/
• http://physics.ucsc.edu/~medling/programming/gnuplot_tutorial_1/index.html
• http://www.gnuplotting.org/