How big are points supposed to be?

[Dima K. <gn...@di...>]

Hi.

I'm observing a specific behavior that probably isn't a bug, but it's
quite annoying. I'd like a comment.

Most of my usage of gnuplot is via the feedgnuplot tool:
https://github.com/dkogan/feedgnuplot

Usually I'm making interactive plots (x11 terminal) as I explore the
data. For instance, to plot 5 points with circles:

  seq 5 | feedgnuplot --with 'points pt 7 ps 2'

Eventually I'm done, and I want to make a pdf to send out in an email:

  seq 5 | feedgnuplot --with 'points pt 7 ps 2' --hardcopy whatever.pdf

This produces the same plot, but targetting a pdf file on a single
landscape-oriented sheet of letter paper. The terminal is set up like
this:

  set terminal pdfcairo noenhanced solid color font ",12" size 11in,8.5in

This works as expected. But the circles appear much bigger in the pdf
than they did on the x11-terminal plot. To make the pdf look the same I
have to manually reduce the size of the points, which is really
annoying.

Does anybody know what the logic is governing the size of the points
gnuplot renders? It's somewhat arbitrary in this case: in the x11
terminal the points stay the same size as you zoom, but with pdfcairo,
naturally everything becomes larger as you zoom in. Is there any
particular rationale to whatever arbitrary choice we have made to
control this? If it's completely arbitrary, can we make a specific
design choice, and then make the terminals agree with each other? I
think making page-sized hardcopies produce comparable point sizes is a
reasonable expectation. Thoughts?