CODEWITHSUNDEEP
rdatedatetime
user7993479
user7993479

Reputation:

Comparing date ranges between different length vectors in R

I am having a little bit of trouble with the below example and any help would be greatly appreciated.

I have two vectors x and y. x is a vector of length 78,725 which contains a date range from "2017-04-23 06:55:00 UTC" to "2017-04-27 17:00:52 UTC" but the interval of time between each element differs from 1 second to a couple of hours. y is a vector of length 8640 which contains a date range from "2017-04-23 00:00:00 UTC" to "2017-04-23 23:59:50 UTC" in increments of 10 seconds. I would like to identify which x >= y and x < y

SAMPLE DATA:

x <- as.POSIXct(c("2017-04-24 18:32:35", "2017-04-24 14:01:03", "2017-04-24 17:51:35",
                  "2017-04-24 15:42:22", "2017-04-24 13:00:51", "2017-04-24 16:56:28",
                  "2017-04-24 17:17:32", "2017-04-24 15:03:34", "2017-04-24 22:40:47",
                  "2017-04-23 17:37:15"), tz = "UTC")
base.date <- as.POSIXct("2017-04-23 0:00:00", tz = "UTC")
every = 10
seconds.in.day = 60*60*24
y <- seq(base.date, length = seconds.in.day / every, by = every)

RESULTS I WANT:

The 10th position of x i.e. "2017-04-23 17:37:15 UTC" is between y element 6344 and 6345.

TRIED THE FOLLOWING:

mapply(function(x, y) x >= y & x < y, as.data.frame(x), as.data.frame(y))

and 

Position(function(x) x >= y & x < y, x)

and

vapply(x, function(x) x >= y & x < y, logical(NROW(x)))

None of these have returned what I am wanting

Upvotes: 0

Views: 100

Answers (1)

Mark Panny
Mark Panny

Reputation: 92

You sample data is difficult because only one of the observations in x falls within the range of y. So I've written the following to account for that. Give this a try...

# Filter down only to observations within the date range of y
 x_range <- x[max(y) >= x & min(y) <= x]

 for (i in length(x_range)) {
   upper.y.index <- vector('numeric')
   upper.y.index[i] <- which.max(y < x_range[i])

   lower.y.index <- vector('numeric')
   lower.y.index[i] <- which.max(y >= x_range[i])
 }


 upper.y.index
 [1] 1
 lower.y.index
 [1] 6345

Upvotes: 0

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