Upset plots are a way of visualising common sets, `gg_miss_upset`

shows the
number of missing values for each of the sets of data. The default option
of `gg_miss_upset`

is taken from `UpSetR::upset`

- which is to use up to 5
sets and up to 40 interactions. We also set the ordering to by the
frequency of the intersections. Setting `nsets = 5`

means to look at 5
variables and their combinations. The number of combinations or rather
`intersections`

is controlled by `nintersects`

. If there are 40
intersections, there will be 40 combinations of variables explored. The
number of sets and intersections can be changed by passing arguments `nsets = 10`

to look at 10 sets of variables, and `nintersects = 50`

to look at 50
intersections.

## Arguments

- data
data.frame

- order.by
(from UpSetR::upset) How the intersections in the matrix should be ordered by. Options include frequency (entered as "freq"), degree, or both in any order. See

`?UpSetR::upset`

for more options- ...
arguments to pass to upset plot - see

`?UpSetR::upset`