Group isolates

[andrewjmc]

Hello,

Thank you for this tremendously useful package. It does so much out of the box and is already proving useful to me.

I love the flexibility afforded by the first_isolate function. However, for some analyses, it would be useful to know the "secondary" isolates which match with a first isolate. Given the way in which is_first_isolate is coded, it doesn't seem immediately obvious if a simple modification could allow a "group_isolates" function which returns a group number (1:n). This way it would be easy to count the number of times a given isolate (however defined) has been identified, and when.

Thanks for your thoughts.

Andrew