aggregate data by 5min excluding max and min

Question

I have a data-frame likeso:

Time    <- seq.POSIXt(as.POSIXct("2017-11-14 00:01:00 CET"), as.POSIXct("2017-11-14 00:15:00 CET"), units = "minute", by=60)
A <- c(2,3,5,2,5,8,17,3,5,8,17,3,5,1,5)
B <- c(1,1,2,1,2,1,2,2,2,4,6,7,8,8,9)

DF <- data.frame(Time=Time, A=A, B=B)

and i want a "newDF" where I aggregate data by 5min, excluding however, for each column, the max/min value before the aggregation.

Using dplyr i get to something like this:

DF$TimeStamp_round<-floor_date(DF$Time,unit="5 minutes")
DF<-DF %>%
  group_by(TimeStamp_round) %>%
  mutate(TimeStamp_count = cur_group_id())

newDF<-DF %>%
  group_by(TimeStamp_count) %>%
  summarise(across(where(is.numeric), mean))

but i still don´t manage to exclude the max/min value before the summarise() function in newDF

note: I do not want to do it manually for each column, because in the real DF the columns are 350

Answer 1

We can remove the range of values before taking the mean after grouping by 'TimeStamp_round'

library(dplyr)
DF %>%
     group_by(TimeStamp_round) %>% 
     summarise(across(A:B, ~ mean(.[!. %in% range(.)])), .groups = 'drop')

---

Or if there are more columns and want to get the mean only for numeric

DF %>%
    select(-Time) %>%
    group_by(TimeStamp_round) %>% 
    summarise(across(where(is.numeric), 
           ~ mean(.[!. %in% range(.)])), .groups = 'drop')