Given a data frame with a variable that contains an unpredictable number of records, how do I gather() this into a long form dataset? If all entries in a column had the same number of pieces of information, I would split them into multiple columns first and then gather, but in this case, some rows have just one value for this variable, but others have arbitrarily many, with a regular separator between.
In searching, I found someone who accomplishes the opposite of this question, see here:
https://markhneedham.com/blog/2015/06/27/r-dplyr-squashing-multiple-rows-per-group-into-one/
In other words, my desired transformation is:
1 Andy Roddick 2009
2 David Nalbandian 2005
3 Grigor Dimitrov 2014
4 Marcos Baghdatis 2006
5 Rafael Nadal 2011, 2010, 2008
6 Roger Federer 2012
Into this:
winner years
1 Andy Roddick 2009
2 David Nalbandian 2005
3 Grigor Dimitrov 2014
4 Marcos Baghdatis 2006
5 Rafael Nadal 2011
6 Roger Federer 2012
7 Rafael Nadal 2010
8 Rafael Nadal 2008
Where I know the separating character, but don't have an upper bound on how many years may appear in each row of the first dataframe. Is there a way to get gather() to do this?
