On Thu, Jun 3, 2010 at 8:04 PM, Gabor Grothendieck <[email protected]> wrote: > Replace the non-events with NA and then use na.locf from the zoo > package to move the last event date up to give lastEvent. > Then simply select those rows whose lastEvent date is at least 14 days > ago or if the row itself is an Event: > >> library(zoo) # na.locf >> >> lastEvent <- with(exData, na.locf(ifelse(Event, Datebegin, NA), na.rm = >> FALSE)) >> exData[beg >= lastEvent + 14 | exData$Event, ]
The last line should have been: exData[exData$Datebegin >= lastEvent + 14 | exData$Event, ] > Datebegin Event > 1 2009-08-20 TRUE > 2 2009-11-21 FALSE > 3 2009-11-28 FALSE > 4 2010-01-12 FALSE > 5 2010-01-18 FALSE > 6 2010-01-23 FALSE > 7 2010-02-21 FALSE > 8 2010-03-03 FALSE > 9 2010-04-06 FALSE > 10 2010-04-16 FALSE > 11 2010-05-22 TRUE > 12 2010-05-27 TRUE > 13 2009-09-08 TRUE > 14 2009-10-01 FALSE > 15 2009-10-06 FALSE > 16 2009-10-09 FALSE > 17 2009-10-11 TRUE > 19 2009-10-28 FALSE > 20 2009-10-31 FALSE > > > On Thu, Jun 3, 2010 at 10:23 AM, Gustaf Rydevik > <[email protected]> wrote: >> Hi all, >> >> >> I wonder if there is any way to calculate a moving average on an >> irregular time series, or use the rollapply function in zoo? >> I have a set of dates where I want to check if there has been an event >> 14 days prior to each time point in order to mark these timepoints for >> removal, and can't figure out a good way to do it. >> >> Many thanks in advance! >> >> Gustaf >> >> >> Example data: >> >> exData<-structure(list(Datebegin = structure(c(14476, 14569, 14576, 14621, >> 14627, 14632, 14661, 14671, 14705, 14715, 14751, 14756, 14495, >> 14518, 14523, 14526, 14528, 14529, 14545, 14548), class = "Date"), >> Event = c(TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, >> FALSE, FALSE, FALSE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, >> TRUE, FALSE, FALSE, FALSE)), .Names = c("Datebegin", "Event" >> ), row.names = c(NA, 20L), class = "data.frame") >> >> ###In this example, row 18 is a date less than 14 days after an event >> and should be marked for removal. >> >> >> >> -- >> Gustaf Rydevik, M.Sci. >> tel: +46(0)703 051 451 >> address:Essingetorget 40,112 66 Stockholm, SE >> skype:gustaf_rydevik >> >> ______________________________________________ >> [email protected] 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. >> > ______________________________________________ [email protected] 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.
