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.dalga...@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@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? ______________________________________________ R-help@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.