Reputation: 97
I have search around and find similar questions but can make it work for my data.
I have a data frame with start and end dates, as well as several other factors. Ideally, the start date of a row should be posterior to the end date of any previous row, but the data has duplicated starts or ends, and sometimes the interval of the dates overlap.
I tried to make a reproducible example:
df = data.frame(start=c("2018/04/15 9:00:00","2018/04/15 9:00:00","2018/04/16 10:20:00","2018/04/16 15:30:00",
"2018/04/17 12:40:00","2018/04/17 18:50:00"),
end=c("2018/04/16 8:00:00","2018/04/16 7:10:00","2018/04/17 18:20:00","2018/04/16 16:30:00",
"2018/04/17 16:40:00","2018/04/17 19:50:00"),
value=c(10,15,11,13,14,12))
I was able to remove the duplicated (end or start dates), but I can't remove the overlapping intervals. I want to create a loop that "cleans" the intervals contained within any larger interval. So the results looks like this:
result = df[c(1,3,6),]
I thought I could make a loop that would "clean" both duplicates and overlapping intervals, but I can't make it work.
Any suggestions?
Upvotes: 2
Views: 482
Reputation: 1061
Alternative approach is to use %within%
of the lubridate()
package:
library(lubridate)
# transform characters to dates
start_time <- as_datetime(df[ , "start"], tz = "UTC")
end_time <- as_datetime(df[ , "end"], tz = "UTC")
# construct intervals
start_end_intrvls <- interval(start_time, end_time)
# find indices of the non-within intervals
not_within <- !(sapply(FUN = function(i) any(start_end_intrvls[i] %within% start_end_intrvls[-i]),
X = seq(along.with = df[ , "start"])))
df[not_within, ]
# start end value
# 1 2018/04/15 9:00:00 2018/04/16 8:00:00 10
# 3 2018/04/16 10:20:00 2018/04/17 18:20:00 11
# 6 2018/04/17 18:50:00 2018/04/17 19:50:00 12
The as_datetime()
function causes an error when being applied to a tibble:
as_datetime(tibble("2018/04/15 9:00:00"), tz = "UTC")
Error in as.POSIXct.default(x) : do not know how to convert 'x' to class “POSIXct”
The solution above may be modified to resolve this issue with substitution of the as_datetime()
with the as.POSIXlt()
:
df_tibble <- tibble(start=c("2018/04/15 9:00:00","2018/04/15 9:00:00","2018/04/16 10:20:00",
"2018/04/16 15:30:00", "2018/04/17 12:40:00","2018/04/17 18:50:00"),
end=c("2018/04/16 8:00:00","2018/04/16 7:10:00","2018/04/17 18:20:00","2018/04/16 16:30:00",
"2018/04/17 16:40:00","2018/04/17 19:50:00"), value=c(10,15,11,13,14,12))
start_time_lst <- lapply(FUN = function(i) as.POSIXlt(as.character(df_tibble[i , "start"]),
tz = "UTC"),
X = seq(along.with = unlist(df_tibble[ , "start"])))
end_time_lst <- lapply(FUN = function(i) as.POSIXlt(as.character(df_tibble[ i, "end"]),
tz = "UTC"),
X = seq(along.with = unlist(df_tibble[ , "end"])))
start_end_intrvls <- lapply(function(i) interval(start_time_lst[[i]] , end_time_lst[[i]]),
X = seq(along.with = unlist(df_tibble[ , "start"])))
not_within <- sapply(function(i) !(any(unlist(Map(`%within%`,
start_end_intrvls[[i]], start_end_intrvls[-i])))),
X = seq(along.with = unlist(df_tibble[ , "start"])))
Upvotes: 1
Reputation: 25225
The data.table
package is suited for this kind of problem using the overlapping join function foverlaps
(inspired by findOverlaps function from the Bioconductor package IRanges) and then an anti-join (data.table syntax is B[!A, on]
) to remove those inner intervals.
library(data.table)
cols <- c("start", "end")
setDT(df)
df[, (cols) := lapply(.SD, function(x) as.POSIXct(x, format="%Y/%m/%d %H:%M:%S")), .SDcols=cols]
setkeyv(df, cols)
anti <- foverlaps(df, df, type="within")[start!=i.start | end!=i.end | value!=i.value]
df[!anti, on=.(start=i.start, end=i.end, value=i.value)]
# start end value
# 1: 2018-04-15 09:00:00 2018-04-16 08:00:00 10
# 2: 2018-04-16 10:20:00 2018-04-17 18:20:00 11
# 3: 2018-04-17 18:50:00 2018-04-17 19:50:00 12
Upvotes: 1