output.png from gnuplot is not as good as the figure from prompt shell

Question

I often plot graphs in gnuplot prompt shell, like this:

gunuplot> plot sin(x) with linespoints pointtype 3

and the figure showe

Answer 1

Comment: you use a JPEG file as an example. You should probably never use JPEG for line plots unless they have photographs as backgrounds. JPEG is simply not designed to handle the sharp edges of line drawings.