Add set.lags to gglagplot

[alepmaros]

Hello,

I often use the option/parameter set.lags in the lag.plot function from R to specify exactly which lags I want to plot.

The current gglagplot function only allows you to specify a range of lags (1:lags) and plots only those, so I can't do something like this:

lag.plot(ldeaths, set.lags=c(1, 4, 8, 10), do.lines=FALSE)

I was wondering if you chose to only allow to plot a specified range or if implementing the set.lags is a planned/wanted thing.

[terrytangyuan]

@sinhrks Any thoughts?

[terrytangyuan]

In my opinion, this set.lags is a wanted thing. You are very welcome to open a PR to add that in!