[R] Infinite Series

[Janh Anni]

Wow! So many (simpler) ways to skin a cat.  Thanks!

On Fri, Jul 24, 2015 at 8:07 PM, David Winsemius <dwinsemius at comcast.net>
wrote:

>
> On Jul 24, 2015, at 4:37 PM, Janh Anni 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.
>
> Wouldn't that just mean using sum instead of cumsum?????
>
> Can even check the error from the analytical limit.
>
> > sum(1/(1:100)^2) - pi^2/6
> [1] -0.009950167
>
>
> >
> > Joseph
> >
> > On Fri, Jul 24, 2015 at 2:02 PM, Jeff Newmiller <
> jdnewmil at 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:<jdnewmil at 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 <annijanh at 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
> >>> <jdnewmil at dcn.davis.ca.us>
> >>> wrote:
> >>>
> >>>> ?cumsum
> >>>>
> >>
> >>>
> ---------------------------------------------------------------------------
> >>>> Jeff Newmiller                        The     .....       .....  Go
> >>> Live...
> >>>> DCN:<jdnewmil at 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 <annijanh at 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 at 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 at 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.
>
> David Winsemius
> Alameda, CA, USA
>
>

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