See ?merge. Also ?merge.zoo in the zoo package and sqldf in the sqldf package (http://sqldf.googlecode.com).
Please read the last line to every message to r-help. On Fri, Nov 7, 2008 at 6:19 PM, t c <[EMAIL PROTECTED]> wrote: > 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. > > ______________________________________________ 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.