Thanks Bill for the email. Your function looks great.
f2<- function(x) x[c(diff(x)<1,TRUE)] f2(a4) #[1] 8 4 4 4 13 12 f2(a3) #[1] 8 1 1 1 13 4 Using the example you provided. set.seed(24) a5 <- sample(20, replace=TRUE, size=1e7) f1New<- function(x) x[c(diff(x)<0,TRUE)|c(x[-length(x)]==x[-1],TRUE)] f3 <- function(x)x[c(which(diff(x)<1),length(x))] #Marion's function (changed `==` to `<`) f1 <- function(x) x[sort(c(which(c(diff(x)<0,TRUE)), which(x[-length(x)] == x[-1])))] identical(f1New(a5),f1(a5)) #[1] TRUE identical(f2(a5),f1(a5)) #[1] TRUE identical(f3(a5),f1(a5)) #[1] TRUE system.time(f1New(a5)) # user system elapsed # 1.884 0.212 2.102 system.time(f1(a5)) # user system elapsed # 1.604 0.268 1.874 system.time(f2(a5)) # user system elapsed # 1.080 0.120 1.206 system.time(f3(a5)) #Marion's function # user system elapsed # 0.856 0.140 0.998 A.K. ----- Original Message ----- From: William Dunlap <wdun...@tibco.com> To: arun <smartpink...@yahoo.com> Cc: Sent: Thursday, May 30, 2013 2:28 PM Subject: RE: [R] Fwd: Obtaing the maximum Also, your suggestion could avoid the relatively expensive call to sort() if you used logical subscripts. Note that, as a subscript, if conditionA and conditionB are logical vectors with the same length and !any(conditionA & conditionB) then sort( c( which(conditionA), which(conditionB) )) is equivalent to conditionA | conditionB so your sort(c(which(c(diff(x)<0,TRUE)), which(x[-length(x)] == x[-1]))) is equivalent to c(diff(x)<0, TRUE) | c(x[-length(x)] == x[-1]), TRUE) where I padded the second part with TRUE to match the lengths. Now x[-length(x)]==x[-1] is the same as diff(x)==0 so you might as well use just c(diff(x) <= 0, TRUE) Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: arun [mailto:smartpink...@yahoo.com] > Sent: Thursday, May 30, 2013 11:13 AM > To: William Dunlap > Subject: Re: [R] Fwd: Obtaing the maximum > > Thanks Bill. > Arun > > > > > ----- Original Message ----- > From: William Dunlap <wdun...@tibco.com> > To: arun <smartpink...@yahoo.com> > Cc: > Sent: Thursday, May 30, 2013 2:07 PM > Subject: RE: [R] Fwd: Obtaing the maximum > > I thought her != should have been a <, but since the original question was > garbled it was > hard to say. > In any case, I was only pointing out that converting the logical subscripts > to integer > subscripts via > which() and length() was not necessary. > > By the way, solutions to problems like this are more easily compared if > presented as > functions > rather than complicated expressions. E.g., instead of > a4[sort(c(which(c(diff(a4)<0,TRUE)), which(a4[-length(a4)] == a4[-1])))] > a3[sort(c(which(c(diff(a3)<0,TRUE)), which(a3[-length(a3)] == a3[-1])))] > I would rather see > f1 <- function(x) x[sort(c(which(c(diff(x)<0,TRUE)), which(x[-length(x)] > == x[-1])))] > f1(a4) > f1(a3) > Then others can quickly compare various algorithms on different datasets. > E.g. > f3 <- function(x)x[c(which(diff(x)<1),length(x))] > a4<-c(c(1,4,5,8),rep(4,3),c(1,8,11,13),8:12) > identical(f1(a4), f3(a4)) > # [1] TRUE > identical(f1(a3), f3(a3)) > # [1] TRUE > a5 <- sample(20, replace=TRUE, size=1e7) > identical(f1(a5), f3(a5)) > # [1] TRUE > system.time(f1(a5)) > # user system elapsed > # 1.23 0.03 1.31 > system.time(f3(a5)) > # user system elapsed > # 0.61 0.00 0.60 > > Bill Dunlap > Spotfire, TIBCO Software > wdunlap tibco.com > > > > -----Original Message----- > > From: arun [mailto:smartpink...@yahoo.com] > > Sent: Thursday, May 30, 2013 10:52 AM > > To: William Dunlap > > Subject: Re: [R] Fwd: Obtaing the maximum > > > > It works with a1. (Already sent a reply to Marion.) > > > > > > a3[c(diff(a3) != 1, TRUE)] > > # [1] 1 5 8 1 1 1 1 8 11 13 4 > > a3[sort(c(which(c(diff(a3)<0,TRUE)), which(a3[-length(a3)] == a3[-1])))] > > #[1] 8 1 1 1 13 4 > > > > > > a4[sort(c(which(c(diff(a4)<0,TRUE)), which(a4[-length(a4)] == a4[-1])))] > > #[1] 8 4 4 4 13 12 > > a4[c(diff(a4) != 1, TRUE)] > > # [1] 1 5 8 4 4 4 1 8 11 13 12 > > A.K. > > > > > > ----- Original Message ----- > > From: William Dunlap <wdun...@tibco.com> > > To: Marion Wenty <marion.we...@kinderrechteinstitut.at>; > > "tryingtolearnag...@gmail.com" <tryingtolearnag...@gmail.com>; > > "smartpink...@yahoo.com" <smartpink...@yahoo.com>; "r-help@r-project.org" > > <r- > > h...@r-project.org> > > Cc: > > Sent: Thursday, May 30, 2013 1:50 PM > > Subject: RE: [R] Fwd: Obtaing the maximum > > > > > or ... a shorter way would be: > > > > > > a1<-c(1,2,3,4,5,1,2,3,1,1,1,2,3,4,5,1,2,3) > > > > > > a1[c(which(diff(a1)!=1),length(a1))] > > > > Or, even shorter, > > a1[c(diff(a1) != 1, TRUE)] > > > > Bill Dunlap > > Spotfire, TIBCO Software > > wdunlap tibco.com > > > > > > > -----Original Message----- > > > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > > > On > Behalf > > > Of Marion Wenty > > > Sent: Thursday, May 30, 2013 10:20 AM > > > To: tryingtolearnag...@gmail.com; smartpink...@yahoo.com; > > > r-help@r-project.org > > > Subject: [R] Fwd: Obtaing the maximum > > > > > > Hi, > > > > > > or ... a shorter way would be: > > > > > > a1<-c(1,2,3,4,5,1,2,3,1,1,1,2,3,4,5,1,2,3) > > > > > > a1[c(which(diff(a1)!=1),length(a1))] > > > > > > Hope it helps. > > > > > > Marion > > > > > > ---------- Forwarded message ---------- > > > From: arun <smartpink...@yahoo.com> > > > Date: 2013/5/29 > > > Subject: Re: [R] Obtaing the maximum > > > To: R help <r-help@r-project.org> > > > > > > > > > Hi, > > > May be this helps: > > > a1<-c(1:5,1:3,rep(1,2),1:5,1:3) > > > a1 > > > # [1] 1 2 3 4 5 1 2 3 1 1 1 2 3 4 5 1 2 3 > > > > > > > > > a1[sort(c(which(c(diff(a1)<0,TRUE)), which(a1[-length(a1)] == a1[-1])))] > > > #[1] 5 3 1 1 5 3 > > > a2<-c(1:2,rep(1,4),1:7,1:3) > > > a2 > > > # [1] 1 2 1 1 1 1 1 2 3 4 5 6 7 1 2 3 > > > a2[sort(c(which(c(diff(a2)<0,TRUE)), which(a2[-length(a2)] == a2[-1])))] > > > #[1] 2 1 1 1 1 7 3 > > > > > > a3<-c(c(1,4,5,8),rep(1,3),c(1,8,11,13),1:4) > > > a3 > > > # [1] 1 4 5 8 1 1 1 1 8 11 13 1 2 3 4 > > > a3[sort(c(which(c(diff(a3)<0,TRUE)), which(a3[-length(a3)] == a3[-1])))] > > > #[1] 8 1 1 1 13 4 > > > > > > a4<-c(c(1,4,5,8),rep(4,3),c(1,8,11,13),8:12) > > > a4 > > > # [1] 1 4 5 8 4 4 4 1 8 11 13 8 9 10 11 12 > > > a4[sort(c(which(c(diff(a4)<0,TRUE)), which(a4[-length(a4)] == a4[-1])))] > > > #[1] 8 4 4 4 13 12 > > > A.K. > > > > > > > > > > > > >Hi all, I have a series whose tpe for that is like series I expose below. > > > > > > > >The thing is if a incremental number ends I´m in the first "type" of > > > >event > > > >in this success is named 5 (because of the maximum is 5). In the series I > > > >have this kind of events 5,3,1,1,5,3 > > > > > > > >But I don´t know extactly a priori what is the maximum and when "stops" > > > >there is some function in r doing something similar this? > > > > > > > >Thans in advance to all. > > > > > > > > > > > >1 > > > >2 > > > >3 > > > >4 > > > >5 > > > >1 > > > >2 > > > >3 > > > >1 > > > >1 > > > >1 > > > >2 > > > >3 > > > >4 > > > >5 > > > >1 > > > >2 > > > >3 > > > > > > ______________________________________________ > > > R-help@r-project.org mailing list > > > 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. > > > > > > > > > > > > -- > > > Mag.a Marion Wenty > > > Wissenschaftliche Mitarbeiterin > > > Institut für Kinderrechte und Elternbildung > > > Ballgasse 2, 6. Stock > > > 1010 Wien > > > > > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.
