I have the following data frame:
sourceid dataelementid value timestamp
11726 10922 34 2016-04-03 02:05:02
11726 10923 9 2016-05-29 10:47:59
11726 10923 9 2016-05-29 03:47:59
11726 10924 19 2016-03-20 02:05:02
11726 10922 18 2016-05-29 10:47:59
12389 10922 23 2016-07-17 02:05:02
12389 10923 12 2016-04-09 02:05:02
12389 10923 3 2016-09-04 02:05:02
12389 10923 30 2016-04-03 02:05:02
12389 10924 23 2016-04-03 02:05:02
12389 10924 17 2016-05-30 02:05:02
12389 10922 15 2016-04-03 02:05:02
45012 10922 33 2016-03-03 02:05:02
45012 10924 11 2016-05-29 10:47:59
As you can see, I have two columns with unique ID's (Sourceid and dataelementid). What I would like to do is to get the most recent data from the data frame and have a new data frame that looks like this:
sourceid dataelementid value timestamp
11726 10922 18 2016-05-29 10:47:59
11726 10923 9 2016-05-29 10:47:59
11726 10924 19 2016-03-20 02:05:02
12389 10922 23 2016-07-17 02:05:02
12389 10923 3 2016-09-04 02:05:02
12389 10924 17 2016-05-30 02:05:02
45012 10922 33 2016-03-03 02:05:02
45012 NA
45012 10924 11 2016-05-29 10:47:59
I have searched for a solution to this but those I have found are only looking at data frames with one column containing the ID's. If a solution to a similar problem to this already exists, it would be great if I could be pointed to it.
Thanks in advance.