Just expand the weekly data set to have an entry for each day and cbind SurveyData with the new Modified.sat.data.
I was having a similar problem but with dates and here was a solution suggested by Gustaf Rydevik using rep() with the each option. ======================================================================== time<-rep(1:24, 365) dates<-seq(as.Date("01012005",format="%d%m%Y"),as.Date("31122005",format="%d%m%Y"),by=1) TimeFrame<-data.frame(time) TimeFrame$dates<-rep(dates,each=24) ========================================================================= --- On Fri, 11/7/08, t c <[EMAIL PROTECTED]> wrote: > From: t c <[EMAIL PROTECTED]> > Subject: [R] Faster way to combine data sets with different date ranges > To: r-help@r-project.org > Received: Friday, November 7, 2008, 6:19 PM > I am trying to combine two data sets, one with daily values > and one with weekly values. SurveyData conatins > environmental data collected on a daily basis. sat.data > contains satellite sea surface temperature that is an > average of satellite measurements over a six day period. I > would like to combine the two files so that my output file > has the daily dates from SurveyData and the weekly average > from sat.data that corresponds to that day. I have written > a loop that does exactly what I want, but it takes a very > long time. Is there a faster way to do this? What I have > so far is below. > Thanks, > Tim > > #Compare dates > for(i in 1:length(SurveyData$Date)) > { > print(i) > for(j in 1:length(sat.data$Date.Start)) > { > if( > sat.data$Date.Start[j]<=SurveyData$Date[i] & > sat.data$Date.End[j]>=SurveyData$Date[i]) > survey.data[i]<- sat.data$data[j] > } > } > > #Create data frame with final data > final.data<-data.frame(SurveyData$Record,SurveyData$Date,survey.data) > > #Write data to file > write.csv(final.data,file="Combined.csv") > > > > > [[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. __________________________________________________________________ Ask a question on any topic and get answers from real people. Go to Yahoo! Answers and share what you know at http://ca.answers.yahoo.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.