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Max consecutive increase in sequence
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Max consecutive increase in sequence
by Marko Milicic
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Hi all R helpers,
I'm trying to comeup with nice and elegant way of "detecting" consecutive increases/decreases in the sequence of numbers. I'm trying with combination of which() and diff() functions but unsuccesifuly. For example: sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1); I'd like to find way to calculate a) maximum consecutive increase = 3 (from 1 to 4) b) maximum consecutive decrease = 5 (from 6 to 1) All ideas are highly welcomed! -- This e-mail and any files transmitted with it are confid...{{dropped:14}} ______________________________________________ R-help@... 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. |
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Re: Max consecutive increase in sequence
by Ingmar Visser
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rle(diff(sq)) could be helpful here,
best, Ingmar On May 13, 2008, at 11:19 PM, Marko Milicic wrote: > Hi all R helpers, > > I'm trying to comeup with nice and elegant way of "detecting" > consecutive > increases/decreases in the sequence of numbers. I'm trying with > combination > of which() and diff() functions but unsuccesifuly. > > For example: > > sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1); > > I'd like to find way to calculate > > a) maximum consecutive increase = 3 (from 1 to 4) > b) maximum consecutive decrease = 5 (from 6 to 1) > > All ideas are highly welcomed! > > > > > > -- > This e-mail and any files transmitted with it are confid... > {{dropped:14}} > > ______________________________________________ > R-help@... 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. ______________________________________________ R-help@... 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. |
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Re: Max consecutive increase in sequence
by Tony Plate
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If the increases or decreases could be any size,
rle(sign(diff(x))) could do it: > x <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1) > r <- rle(sign(diff(x))) > r Run Length Encoding lengths: int [1:5] 3 2 2 5 4 values : num [1:5] 1 0 1 -1 0 > i1 <- which(r$lengths==max(r$lengths[r$values==1]) & r$values==1)[1] > i2 <- which(r$lengths==max(r$lengths[r$values==-1]) & r$values==-1)[1] > i1 [1] 1 > i2 [1] 4 > rbind(up=c(start=cumsum(c(1, r$lengths))[i1], len=r$lengths[i1]), down=c(start=cumsum(c(1, r$lengths))[i2], len=r$lengths[i2])) start len up 1 3 down 8 5 > Ingmar Visser wrote: > rle(diff(sq)) could be helpful here, > best, Ingmar > > On May 13, 2008, at 11:19 PM, Marko Milicic wrote: > >> Hi all R helpers, >> >> I'm trying to comeup with nice and elegant way of "detecting" consecutive >> increases/decreases in the sequence of numbers. I'm trying with >> combination >> of which() and diff() functions but unsuccesifuly. >> >> For example: >> >> sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1); >> >> I'd like to find way to calculate >> >> a) maximum consecutive increase = 3 (from 1 to 4) >> b) maximum consecutive decrease = 5 (from 6 to 1) >> >> All ideas are highly welcomed! >> >> >> >> >> >> -- >> This e-mail and any files transmitted with it are confid...{{dropped:14}} >> >> ______________________________________________ >> R-help@... 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. > > ______________________________________________ > R-help@... 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. > ______________________________________________ R-help@... 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. |
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Re: Max consecutive increase in sequence
by Phil Spector
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I believe the original poster was looking for runs of consecutive
values. Here's a generalization of Tony's solution: findlong = function(seq){ rr = rle(seq) lens = rr$length lens[rr$value == FALSE] = 0 ll = which.max(lens) start = cumsum(c(1,rr$length))[ll] list(start=start,length=rr$lengths[ll]) } > sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1) Then > findlong(diff(sq) == 1) # starts at position 1, run of 3 $start [1] 1 $length [1] 3 > findlong(diff(sq) == -1) # starts at position 8, run of 5 $start [1] 8 $length [1] 5 - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spector@... On Tue, 13 May 2008, Tony Plate wrote: > If the increases or decreases could be any size, rle(sign(diff(x))) could do > it: > >> x <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1) >> r <- rle(sign(diff(x))) >> r > Run Length Encoding > lengths: int [1:5] 3 2 2 5 4 > values : num [1:5] 1 0 1 -1 0 >> i1 <- which(r$lengths==max(r$lengths[r$values==1]) & r$values==1)[1] >> i2 <- which(r$lengths==max(r$lengths[r$values==-1]) & r$values==-1)[1] >> i1 > [1] 1 >> i2 > [1] 4 >> rbind(up=c(start=cumsum(c(1, r$lengths))[i1], len=r$lengths[i1]), > down=c(start=cumsum(c(1, r$lengths))[i2], len=r$lengths[i2])) > start len > up 1 3 > down 8 5 >> > > Ingmar Visser wrote: >> rle(diff(sq)) could be helpful here, >> best, Ingmar >> >> On May 13, 2008, at 11:19 PM, Marko Milicic wrote: >> >>> Hi all R helpers, >>> >>> I'm trying to comeup with nice and elegant way of "detecting" consecutive >>> increases/decreases in the sequence of numbers. I'm trying with >>> combination >>> of which() and diff() functions but unsuccesifuly. >>> >>> For example: >>> >>> sq <- c(1, 2, 3, 4, 4, 4, 5, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1); >>> >>> I'd like to find way to calculate >>> >>> a) maximum consecutive increase = 3 (from 1 to 4) >>> b) maximum consecutive decrease = 5 (from 6 to 1) >>> >>> All ideas are highly welcomed! >>> >>> >>> >>> >>> >>> -- >>> This e-mail and any files transmitted with it are confid...{{dropped:14}} >>> >>> ______________________________________________ >>> R-help@... 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. >> >> ______________________________________________ >> R-help@... 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. >> > > ______________________________________________ > R-help@... 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. > ______________________________________________ R-help@... 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. |
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