Ramnik, a final mail is actually really important: this is to document in the archives, for the benefit of those who found the thread at a later time, that the responses indeed solved the problem.
Other than that, the single most important advice is to - provide a minimal working example of the problem; - state clearly what you expect; - state explicitly what happened instead. Apparently you're doing fine in that regard. B. > On Apr 17, 2017, at 10:25 AM, Bert Gunter <bgunter.4...@gmail.com> wrote: > > (Apparently I hit "send" too early) > > 1. I have cc'ed this to the list, as others may well have some good > suggestions re: books. > > 2. The posting guide is your best resource as to what is appropriate > for the list. I defer to others re: conventions, as I have have been > accused of violating them from time to time. > > 3. R resources abound. RStudio has some recommendations for web > resource on their site worth checking out: > > https://www.rstudio.com/online-learning/#R > > But there are many others that a search would reveal. > > Hadley Wickham has written a couple of books worth checking. I think > that the O'Reilly series might have one or more. It is of course > difficult to judge what "a good book for a newbie" would be in your > mind, but it is hard for me to believe that there aren't at least > several out there. > > -- 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 Mon, Apr 17, 2017 at 1:06 AM, Ramnik Bansal <ramnik.ban...@gmail.com> > wrote: >> Thanks Bert for the reply. It cleared my confusion . >> >> Also am new to the mailing list. Can you please guide me to the mailing list >> norms. For e.g. when I get a reply to my query which imparts me a better >> understanding on the topic, is it a norm to thank the individuals who >> responded, thru a personal mail ? Or it is kind of taken for granted that >> the question has been replied to and an individual thanks-reply to reply is >> not even expected as it will increase the number of mails. >> >> Also what seems to be missing is a good book on R which talks about all >> these nuances even for a newbie who wants to master R. Or maybe am unaware >> of one such book. >> >> -Best >> Ramnik >> >> >> On Mon, Apr 17, 2017 at 10:20 AM, Bert Gunter <bgunter.4...@gmail.com> >> wrote: >>> >>> David et. al.: >>> >>> "this levels is the level where you realize that the `for` function is >>> different from most other R functions. It is really a >>> side-effect-fucntion. " >>> >>> for(), while(), if(), next, etc. are *not* functions. >>> >>> ?for says: "These are the basic control-flow constructs of the R >>> language." >>> >>> They do not "return" values. They control program flow, whence what >>> you call "side effects" are actually expressions that are parsed and >>> evaluated >>> >>> viz. >>> >>>> if(TRUE)10 >>> [1] 10 >>> >>> ## but >>> >>>> if(FALSE) 5 >>> ## nothing is returned, not even NULL >>>> for(i in 1:3) i >>> ## Ditto >>> >>>> z <- NULL >>>> z <- for(i in 1:3)i >>>> z >>> NULL ## still >>> >>> Cheers, >>> Bert >>> >>> >>> >>> >>> 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, Apr 16, 2017 at 8:12 PM, David Winsemius <dwinsem...@comcast.net> >>> wrote: >>>> >>>>> On Apr 16, 2017, at 7:26 PM, Ramnik Bansal <ramnik.ban...@gmail.com> >>>>> wrote: >>>>> >>>>> In the code below >>>>> >>>>> >>>>> *ff <- function(n){ for(i in 1:n) (i+1)}* >>>>> >>>>> *n<-3;ff(n)->op;print(op)* >>>>> >>>>> Why doesnt *print(op) * print 4 and instead prints NULL. >>>>> Isnt the last line of code executed is *i+1 * and therefore that should >>>>> be >>>>> returned instead of NULL >>>>> >>>>> instead if I say >>>>> *ff <- function(n){ (n+1) }* >>>>> >>>>> Then >>>>> *n<-3;ff(n)->op;rm(n);print(op)* >>>>> gives 4 as output. >>>>> >>>>> My question is *Which *is considered as the last line in a functoin for >>>>> the >>>>> purpsoe of default return ? And under what conditions ? >>>> >>>> It's probably a good thing that you are confused. It suggests that you >>>> are actually "getting" the R-paradigm. Unfortunately for the new user of R, >>>> there are several levels of understanding to pass through. First, you >>>> realize that function-results need to be assigned to names in order to >>>> persist. Then there is the next level where you discover that there are >>>> exceptions to that rule: this levels is the level where you realize that >>>> the >>>> `for` function is different from most other R functions. It is really a >>>> side-effect-fucntion. The assignments made within its body actually persist >>>> in the global environment. AND it returns NULL. It shares this anomalous >>>> behavior with `while` and `repeat`.n Almost all functions are invoked with >>>> a >>>> possibly empty argument list. The next and break functions have implicit >>>> paired (empty) parentheses. >>>> >>>> (My personal opinion is that this is not adequately advertised. Perhaps >>>> it is an attempt to get people to migrate away from "Fortran-coding" >>>> behavior?) >>>> >>>> -- >>>> David. >>>> >>>> >>>>> >>>>> -Thanks, >>>>> Ramnik >>>>> >>>>> [[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. >>>> >>>> David Winsemius >>>> Alameda, CA, USA >>>> >>>> ______________________________________________ >>>> 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.