Janh: It sounds like you really need to go through an R tutorial or two before posting further, as this is a pretty basic query. Or am I wrong about this?
An answer: Just use indexing cumsum(1/seq_len(100)^2)[seq(10, to = 100,by = 10)] ## keeps every 10th [1] 1.549768 1.596163 1.612150 1.620244 1.625133 1.628406 1.630750 1.632512 1.633884 [10] 1.634984 But beware FAQ 7.31 for long series. Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Fri, Jul 24, 2015 at 4:37 PM, Janh Anni <annij...@gmail.com> wrote: > Hello Jeff, > > Thanks a lot. I tried it and see that it prints out the entire 100 partial > sums, so I can take the last value as the partial sum for the first 100 > terms. Would there be any way cumsum can print only the nth partial sum, > i.e. the last value in the array, instead of printing the entire array? > Thanks again. > > Joseph > > On Fri, Jul 24, 2015 at 2:02 PM, Jeff Newmiller <jdnew...@dcn.davis.ca.us> > wrote: > >> Please reply-all so the mailing list stays in the loop. >> >> cumsum(1/(1:100)^2) >> >> gives you the partial sums up through i=100. >> --------------------------------------------------------------------------- >> Jeff Newmiller The ..... ..... Go Live... >> DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live >> Go... >> Live: OO#.. Dead: OO#.. Playing >> Research Engineer (Solar/Batteries O.O#. #.O#. with >> /Software/Embedded Controllers) .OO#. .OO#. rocks...1k >> --------------------------------------------------------------------------- >> Sent from my phone. Please excuse my brevity. >> >> On July 24, 2015 10:30:09 AM PDT, Janh Anni <annij...@gmail.com> wrote: >> >Hello Jeff, >> > >> >Thank you so much for the suggestion, I searched cumsum as suggested >> >but >> >not sure it is what I had in mind. For instance if I had the infinite >> >series: [image: Inline image 1] >> > >> >and want to compute the sum of the, say, first 100 terms, how could I >> >use >> >cusum to do that? >> > >> >Thanks again, >> > >> >Janh >> > >> > >> >On Thu, Jul 23, 2015 at 11:51 PM, Jeff Newmiller >> ><jdnew...@dcn.davis.ca.us> >> >wrote: >> > >> >> ?cumsum >> >> >> >> >--------------------------------------------------------------------------- >> >> Jeff Newmiller The ..... ..... Go >> >Live... >> >> DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live >> >> Go... >> >> Live: OO#.. Dead: OO#.. >> >Playing >> >> Research Engineer (Solar/Batteries O.O#. #.O#. with >> >> /Software/Embedded Controllers) .OO#. .OO#. >> >rocks...1k >> >> >> >> >--------------------------------------------------------------------------- >> >> Sent from my phone. Please excuse my brevity. >> >> >> >> On July 23, 2015 8:23:39 PM PDT, Janh Anni <annij...@gmail.com> >> >wrote: >> >> >Dear All, >> >> > >> >> >Does anyone know of any R functions that compute partial sums of >> >> >series? >> >> > >> >> >Thanks in advance! >> >> > >> >> >Janh >> >> > >> >> > [[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. ______________________________________________ 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.
