You can compare the elements that make sense to compare, and fill in the ones that don't make sense to compare yourself using the c function.
Hint: no looping or if function are necessary. v[ seq( 2, length( v ) ] == v[ seq.int( length( v ) - 2 ) ] -- Sent from my phone. Please excuse my brevity. On July 23, 2017 12:04:00 PM PDT, Davide Piffer <pifferdav...@gmail.com> wrote: >No homework. Just a genuine question > >On 23 July 2017 at 22:00, Bert Gunter <bgunter.4...@gmail.com> wrote: >> Homework?? There is a no homework policy on this list. >> >> Cheers, >> Bert >> Bert Gunter >> >> "The trouble with having an open mind is that people keep coming >along >> and sticking things into it." >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) >> >> >> On Sun, Jul 23, 2017 at 11:43 AM, Davide Piffer ><pifferdav...@gmail.com> wrote: >>> I have a df with a vector v. For each element of the vector, I want >to >>> know whether the i-2nd element is the same as the ith element. For >>> example: >>> given >>> v=c(A,C,D,C) the result should be: >>> FALSE,FALSE,FALSE,TRUE. >>> >>> I attempted something using indexing in a for loop such as (bad, >>> incorrect example): >>> for (i in v){ >>> if [i]==[i-2] print T >>> else print F >>> } >>> >>> However, this is obviously wrong. >>> Can someone provide a nice way to solve this? >>> >>> ______________________________________________ >>> 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. ______________________________________________ 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.