[R] How to "bin"/average" time points?

[jim holtman]

try this:

> # create times 9 minutes apart
> time <- seq(as.POSIXct('2010-11-25 00:00'), by = '9 min', length = 480)
> mySamp <- data.frame(time = time, value = sample(1:100, length(time), TRUE))
> # add column to split by hour
> mySamp$hour <- format(mySamp$time, '%Y-%m-%d %H:30')
> # compute the mean for each hour
> tapply(mySamp$value, mySamp$hour, mean)
2010-11-25 00:30 2010-11-25 01:30 2010-11-25 02:30 2010-11-25 03:30
2010-11-25 04:30 2010-11-25 05:30
        54.42857         59.85714         47.50000         45.71429
     40.28571         56.50000
2010-11-25 06:30 2010-11-25 07:30 2010-11-25 08:30 2010-11-25 09:30
2010-11-25 10:30 2010-11-25 11:30
        46.57143         47.14286         34.00000         53.85714
     50.28571         36.00000
2010-11-25 12:30 2010-11-25 13:30 2010-11-25 14:30 2010-11-25 15:30
2010-11-25 16:30 2010-11-25 17:30
        31.57143         44.57143         42.50000         52.42857
     54.14286         44.66667
2010-11-25 18:30 2010-11-25 19:30 2010-11-25 20:30 2010-11-25 21:30
2010-11-25 22:30 2010-11-25 23:30
        50.28571         60.57143         36.00000         42.14286
     65.14286         37.50000
2010-11-26 00:30 2010-11-26 01:30 2010-11-26 02:30 2010-11-26 03:30
2010-11-26 04:30 2010-11-26 05:30
        51.71429         58.85714         48.50000         45.00000
     44.00000         38.00000
2010-11-26 06:30 2010-11-26 07:30 2010-11-26 08:30 2010-11-26 09:30
2010-11-26 10:30 2010-11-26 11:30
        56.00000         34.14286         64.66667         51.42857
     57.57143         44.50000
2010-11-26 12:30 2010-11-26 13:30 2010-11-26 14:30 2010-11-26 15:30
2010-11-26 16:30 2010-11-26 17:30
        65.00000         59.57143         63.50000         52.57143
     36.85714         63.33333
2010-11-26 18:30 2010-11-26 19:30 2010-11-26 20:30 2010-11-26 21:30
2010-11-26 22:30 2010-11-26 23:30
        44.85714         64.85714         63.00000         62.57143
     62.00000         57.00000
2010-11-27 00:30 2010-11-27 01:30 2010-11-27 02:30 2010-11-27 03:30
2010-11-27 04:30 2010-11-27 05:30
        26.71429         33.57143         37.50000         67.00000
     47.85714         63.00000
2010-11-27 06:30 2010-11-27 07:30 2010-11-27 08:30 2010-11-27 09:30
2010-11-27 10:30 2010-11-27 11:30
        40.28571         46.42857         54.50000         41.00000
     51.00000         58.33333
2010-11-27 12:30 2010-11-27 13:30 2010-11-27 14:30 2010-11-27 15:30
2010-11-27 16:30 2010-11-27 17:30
        62.14286         52.28571         75.33333         43.71429
     53.14286         27.50000
2010-11-27 18:30 2010-11-27 19:30 2010-11-27 20:30 2010-11-27 21:30
2010-11-27 22:30 2010-11-27 23:30
        33.42857         56.85714         57.83333         51.00000
     57.71429         38.66667


On Thu, Nov 25, 2010 at 3:49 PM, DonDolowy <kevin.dalgaard at gmail.com> wrote:
>
> Dear all,
>
> I am pretty new to R only having an introduction course, so please bare with
> me. I am doing my PhD at The Max Planck Institute of Immunobiology where I
> am analyzing some calorimetry data from some mice.
> I have a spreadsheet consisting of measurements of the respiratory exchange
> rate at different time points measured every 9 minutes over some days.
> My goal is "bin"/average the time points of each hour to only one
> measurements.
>
> E.g.
> [Time] - [Measurement]
> 12.09 - 0.730
> 12.18 - 0.732
> 12.27 - 0.743
> 12.36 - 0.757
> 12.45 - 0.781
> 12.54 - 0.731
> --> should be averaged to fx one time point and one value, fx:
> 12.30 - [average of the six measurements]
>
> I know how to average the measurements in a whole column but how to average
> every six measurements automatically and also how to average every six time
> points and make a new sheet consisting of these data?
>
> I hope you guys are able to help, since we are really stuck here. I can of
> course do it manually but with >8000 measurements it will take lots of time.
>
> Thank you very much.
>
> Best regards,
> Kevin Dalgaard
> --
> View this message in context: http://r.789695.n4.nabble.com/How-to-bin-average-time-points-tp3059509p3059509.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?