[R] Aggregating Data

[Jeff Reichman]

R-Help

Please disregard as I figure something out, unless there is a more elegant
way ...

myData.sum <- aggregate(x =
myData[c("s72","s79","s82","s83","s116","s119")],
                     FUN = sum,
                     by = list(Group.date = myData$shortdate))
> head(myData.sum)
  Group.date s72 s79 s82 s83 s116 s119
1 2016/10/03  75  74  36  33   96   10
2 2016/10/04  90  76  40  56  137    9
3 2016/10/05 106  83  38  51   90   10
4 2016/10/06  93  87  31  43   97   15
5 2016/10/07  88  96  33  48  125   12
6 2016/10/08  64  39  22  30   63    5



I created a "shortdate"  for the purpose of aggregating each var (S72 .S119)
by daily sum , but not sure how to handle using a POSIXlt object.

> myData$shortdate <- strftime(myData$time, format="%Y/%m/%d")
> head(myData)
                 time s72 s79 s82 s83 s116 s119  shortdate
1 2016-10-03 00:00:00   0   0   1   0    0    0 2016/10/03
2 2016-10-03 01:00:00   0   0   0   0    0    0 2016/10/03
3 2016-10-03 02:00:00   0   0   0   0   24    0 2016/10/03
4 2016-10-03 03:00:00   1   0   0   0    0    0 2016/10/03
5 2016-10-03 04:00:00   0   0   0   0    1    0 2016/10/03
6 2016-10-03 05:00:00   1   0   1   0    0    1 2016/10/03

Jeff


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