Thanks, I meant if there are missing data at the beginning and end of a dataframe, how to interpolate according to available data?
For example, the A column has missing values at the beginning and end, how to interpolate linearly between 10 and 12 for the missing values? df <- data.frame(A=c(NA, NA,10,11,12, NA),B=c(5,5,4,3,4,5),C=c(3.3,4,3,1.5, 2.2,4),time=as.Date(c("1990-01-01","1990-02- 07","1990-02-14","1990-02-28","1990-03-01","1990-03-20"))) On Thu, Jul 21, 2016 at 4:48 PM, William Dunlap <wdun...@tibco.com> wrote: > Try approx(), as in: > > df <- > data.frame(A=c(10,11,12),B=c(5,5,4),C=c(3.3,4,3),time=as.Date(c("1990-01-01","1990-02-07","1990-02-14"))) > with(df, approx(x=time, y=C, xout=seq(min(time), max(time), by="days"))) > > Do you notice how one can copy and paste that example out of the > mail an into R to see how it works? It would help if your questions > had that same property - show how the example data could be created. > > > Bill Dunlap > TIBCO Software > wdunlap tibco.com > > On Thu, Jul 21, 2016 at 3:34 PM, lily li <chocol...@gmail.com> wrote: > >> I have a question about interpolating missing values in a dataframe. The >> dataframe is in the following, Column C has no data before 2009-01-05 and >> after 2009-12-31, how to interpolate data for the blanks? That is to say, >> interpolate linearly between these two gaps using 5.4 and 6.1? Thanks. >> >> >> df >> time A B C >> 2009-01-01 3 4.5 >> 2009-01-02 4 5 >> 2009-01-03 3.3 6 >> 2009-01-04 4.1 7 >> 2009-01-05 4.4 6.2 5.4 >> ... >> >> 2009-11-20 5.1 5.5 6.1 >> 2009-11-21 5.4 4 >> ... >> 2009-12-31 4.5 6 >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.