Timeline with events only

[mhwombat]

Thank you for making this package available. I would like to be able to generate a timeline with just events, no time periods. I tried to accomplish this by passing a data frame with no rows as the first argument, but got an error.

> ww2a <- ww2[-c(1:8),]
> timeline(ww2a, ww2.events)
Error in `$<-.data.frame`(`*tmp*`, "ymax", value = NA) : 
  replacement has 1 row, data has 0
> ww2a
[1] Person    Group     StartDate EndDate  
<0 rows> (or 0-length row.names)