This has been solved in an earlier post: http://www.nabble.com/linear-interpolation-of-multiple-random-time-series-to11694879.html
On Thu, Dec 11, 2008 at 4:38 PM, tsunhin wong <thjw...@gmail.com> wrote: > Dear all R users, > > I am going to use R to process some of my physiological data about eye. > > The problem is the recording machine does not sample in a reliably > constant rate: the time intervals between data sampled can vary from > 9msec to ~120msec, while most around in the 15-30msec range. > The below is a fraction of a single data file of a trial: > > Time CursorX CursorY Pupilsize > 1811543 -1 -1 -1 > 1811563 -1 -1 -1 > 1811584 511 370 4.175665 > 1811603 511 368 4.181973 > 1811624 521 368 4.210732 > 1811644 512 377 4.149632 > 1811664 524 377 4.275845 > 1811684 518 368 4.236212 > 1811703 516 370 4.238384 > 1811725 507 364 4.181157 > 1811744 509 371 4.185016 > 1811764 509 377 4.231987 > 1811784 514 387 4.252449 > 1811802 515 388 4.273726 > > My goal is to "resample" these data so that the "Time" column > increments by a regular interval, and the other columns of data are > the averages (or estimates) at the point in time according to > available data points. > I have done something that I use a regular interval that is larger > than the naturally occurring record machine, i.e. > 120msec for > example, and acquire an average of the available data points for any > particular regular time interval. > > Now, I need to achieve resampling for smaller regular interval: i.e. > 5msec intervals, and interpolate / intrapolate the missing data points > from the available ones. > i.e. I may have to split up data points into the number of the regular > intervals that it may occupied in time. > > Do you know if there is any package that is doing something similar? > And because of the size of the data and computational demand (1500 > files each with 2000-8000+ lines), can you suggest me some > (algorithmically) more efficient way of doing this? > > Thanks a lot! > > Regards, > > John > > ______________________________________________ > 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. > -- Mike Lawrence Graduate Student Department of Psychology Dalhousie University www.thatmike.com Looking to arrange a meeting? Do so at: http://www.timetomeet.info/with/mike/ ~ Certainty is folly... I think. ~ [[alternative HTML version deleted]] ______________________________________________ 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.
