CODEWITHSUNDEEP
rdataframetime-seriesdplyrdata-processing
jjdblast
jjdblast

Reputation: 535

R aggregate data in round 10 minutes

I have a R dataframe, df, like this:

    WIFIAPTag          passengerCount      timeStamp            MAC
1    E1-1A-1<E1-1-01>       15       2016-09-10 18:55:04    5869.6c54.d040
750  E1-1A-1<E1-1-01>       14       2016-09-10 18:56:01    5869.6c54.d040
1499 E1-1A-1<E1-1-01>       18       2016-09-10 18:57:01    5869.6c54.d040 
2248 E1-1A-1<E1-1-01>       17       2016-09-10 18:58:02    5869.6c54.d040 
2997 E1-1A-1<E1-1-01>       17       2016-09-10 18:59:01    5869.6c54.d040 
3746 E1-1A-1<E1-1-01>       14       2016-09-10 19:00:01    5869.6c54.d040 
3746 E1-1A-1<E1-1-01>       1        2016-09-10 19:05:01    5869.6c54.d040

Now I want to aggregate this dataframe every 10 minutes, like this:

    WIFIAPTag          passengerCount      timeStamp            MAC
1    E1-1A-1<E1-1-01>       81       2016-09-10 18:50:00    5869.6c54.d040
2    E1-1A-1<E1-1-01>       15       2016-09-10 19:00:00    5869.6c54.d040

I using aggregate and cut in R like this:

output <- aggregate(passengerCount ~ cut(timeStamp, breaks = "10 mins"), df, sum)

But I can only get the data start from 2016-09-10 18:55:00:

output
    WIFIAPTag           timeStamp passengerCount
1 E1-1A-1<E1-1-01> 2016-09-10 18:55:00             95
2 E1-1A-1<E1-1-01> 2016-09-10 19:05:00             1

How can I make the output start from 2016-09-10 18:50:00 ?

Upvotes: 1

Views: 1742

Answers (1)

Shape
Shape

Reputation: 2952

Giving a value for breaks like "10 mins" will partition the interval using the first and the last date with 10 min segments.

Instead, choose your breaks explicitly:

(Using lubridate, since I prefer not to hardcode the lowest and highest values)

library(lubridate)

lowtime <- min(df$timeStamp)
hightime <- max(df$timeStamp)

# Set the minute and second to the nearest 10 minute value
minute(lowtime) <- floor(minute(lowtime)/10) * 10
minute(hightime) <- ceiling(minute(hightime)/10) * 10
second(lowtime) <- 0
second(hightime) <- 0

# Set the breakpoints at 10 minute intervals
breakpoints <- seq.POSIXt(lowtime, hightime, by = 600)
output <- aggregate(passengerCount ~ cut(timeStamp, breaks = breakpoints), df, sum)

Upvotes: 3

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