I have a dataframe containing location data of different animals. Each animal has a unique id and each observation has a time stamp and some further metrics of the location observation. See a subset of the data below. The subset contains the first two observations of each id.
> sub
id lc lon lat a b c date
1 111 3 -79.2975 25.6996 414 51 77 2019-04-01 22:08:50
2 111 3 -79.2975 25.6996 414 51 77 2019-04-01 22:08:50
3 222 3 -79.2970 25.7001 229 78 72 2019-01-07 20:36:27
4 222 3 -79.2970 25.7001 229 78 72 2019-01-07 20:36:27
5 333 B -80.8211 24.8441 11625 6980 37 2018-12-17 20:45:05
6 333 3 -80.8137 24.8263 155 100 69 2018-12-17 21:00:43
7 444 3 -80.4535 25.0848 501 33 104 2019-10-20 19:44:16
8 444 1 -80.8086 24.8364 6356 126 87 2020-01-18 20:32:28
9 555 3 -77.7211 24.4887 665 45 68 2020-07-12 21:09:17
10 555 3 -77.7163 24.4897 285 129 130 2020-07-12 21:10:35
11 666 2 -77.7221 24.4902 1129 75 66 2020-07-12 21:09:02
12 666 2 -77.7097 24.4905 314 248 164 2020-07-12 21:11:37
13 777 3 -77.7133 24.4820 406 58 110 2020-06-20 11:18:18
14 777 3 -77.7218 24.4844 170 93 107 2020-06-20 11:51:06
15 888 3 -79.2975 25.6996 550 34 79 2017-11-25 19:10:45
16 888 3 -79.2975 25.6996 550 34 79 2017-11-25 19:10:45
However, I need to do some data housekeeping, i.e. I need to include the day/time and location each animal was released. And after that I need to filter out observations for each animal that occurred pre-release of the corresponding animal.
I have a an additional dataframe that contains the necessary release metadata:
> stack
id release lat lon
1 888 2017-11-27 14:53 25.69201 -79.31534
2 333 2019-01-31 16:09 25.68896 -79.31326
3 222 2019-02-02 15:55 25.70051 -79.31393
4 111 2019-04-02 10:43 25.68534 -79.31341
5 444 2020-03-13 15:04 24.42892 -77.69518
6 666 2020-10-27 09:40 24.58290 -77.69561
7 555 2020-01-21 14:38 24.43333 -77.69637
8 777 2020-06-25 08:54 24.42712 -77.76427
So my question is: how can I add the release information (time and lat/lon) to the dataframe fore each id (while the columns a, b, and c can be NA). And how can I then filter out the observations that occured before each animal's release time? I have been looking into possibilites using dplyr but was not yet able to resolve my issue.