CODEWITHSUNDEEP
r
user3022875
user3022875

Reputation: 9018

Aggregate function in R not working with POSIXct

I'd like to aggregate my data.

time<- as.POSIXct(c("2014-12-10 00:11:02","2014-12-10 00:11:02","2014-12-10 00:11:03"), tz= "GMT")
shares<-c(1,2,3)
price<-c(48, 48, 49)
dat<-data.frame(time= as.factor(time), price= price, size =shares)
dat

here is what dat looks like:

             time price size
1 2014-12-10 00:11:02    48    1
2 2014-12-10 00:11:02    48    2
3 2014-12-10 00:11:03    49    3

now I try to aggregate dat

aggregate(x=dat, by = list( as.factor(dat$size)), formula = cbind(dat$time, dat$price) ~ as.numeric(dat$size), FUN="sum")

I want to aggregate the shares column in dat across time and price so it looks like this:

time                  price  size
2014-12-10 00:11:02    48    3
2014-12-10 00:11:03    49    3

any ideas? Thank you.

Upvotes: 1

Views: 1234

Answers (1)

nacnudus
nacnudus

Reputation: 6528

Either

aggregate(x = dat$size, by = list(time, price), FUN = "sum")

              Group.1 Group.2 x
1 2014-12-10 00:11:02      48 3
2 2014-12-10 00:11:03      49 3

Or

aggregate(size ~ time + price, data = dat, FUN = "sum")

                 time price size
1 2014-12-10 00:11:02    48    3
2 2014-12-10 00:11:03    49    3

These correspond to the docs for ?aggregate, which give possible forms:

aggregate(x, by, FUN, ..., simplify = TRUE)
aggregate(formula, data, FUN, ..., subset, na.action = na.omit)

Your attempt mixed these forms up together.

Upvotes: 3

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