[R] How to create a readable plot in R with 10000+ values in a dataframe

[Abby Spurdle]

On Sat, Jul 25, 2020 at 12:40 AM Martin Maechler
<maechler using stat.math.ethz.ch> wrote:
> Good answers to this question will depend very much on how many
> 'Machine' and 'Region' levels there are.

I second that.
And unless I missed something, the OP hasn't answered this question, as such.
But "10k+" combinations, does imply around 100 levels each.

Another important question is, are the combinations unique or not?

It would be possible to create an (approx):
    100x100 heatmap of boolean values, for unique combinations, or;
    100x100 heatmap of counts (or density), for non-unique combinations.

But unless there's some meaningful order to the levels, the resulting
plot may end up looking like a $3 pizza.
I'm unable to comment on possible exploratory value, but I doubt that
this is a good approach, for presentation purposes.

If the goal was some sort of ranking, a textual summary, may work better...?
Or you could plot relevant subsets of the data...