[R] Density over time intervals

Hello R community, I have recorded online/offline timestamps per user that looks like this: username,online_time,offline_time a,2011-11-01 16:16:56.692572+01,2011-11-01 21:06:16.388903+01 a,2011-11-01 21:07:14.204367+01,2011-11-01 21:34:21.47081+01 a,2011-11-01 21:38:09.501356+01,2011-11-01 21:53

[R] Density over time intervals

Hi, I have recorded online/offline timestamps per user that looks like this: username,online_time,offline_time a,2011-11-01 16:16:56.692572+01,2011-11-01 21:06:16.388903+01 a,2011-11-01 21:07:14.204367+01,2011-11-01 21:34:21.47081+01 a,2011-11-01 21:38:09.501356+01,2011-11-01 21:53:45.272321+