Re: [R] Counter in a For Loop - Efficiency Issue
without a reproducible sample, it is hard to tell, but I will give it a shot. Maybe it's possible to merge your M with M2: merge(M, M2) If you only want to count times, you can use seq_along(x) in a by function eg: dat <- data.frame(person=rep(c(1,2,3), each=5), time=rnorm(15)) by(dat$person, dat$person, function(x) seq_along(x)) Ofcourse you can use any of the other vectorisation functions (lapply, apply, aggregate, ) HTH Bart -- View this message in context: http://r.789695.n4.nabble.com/Counter-in-a-For-Loop-Efficiency-Issue-tp3253674p3253698.html Sent from the R help mailing list archive at Nabble.com. __ 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.
Re: [R] Counter in a For Loop - Efficiency Issue
On Wed, Feb 02, 2011 at 09:35:28AM +0200, Leendert Punt wrote:
> I have a 32000 x 14 matrix (M) where entry (x, y) corresponds to
> person x at a discrete time y. I then have a matrix (M2) of 6 x 2
> where each entry is a an event by a person that is in the above 32000
> and at a time that is in the range of the discrete time points above.
> I want to populate the another matrix (M3) such that (x, y) is the
> number of events of person x between times y-1 and y. This is simple
> to code, (I just put the discrete time points and the 32000 people in
> their own vectors, V1 and V2):
>
>
> for (i in 1:32000){
> for (j in 1:6){
>
> for (k in 2:14){
>
> if (M2[1, j] == V2[i] & M2[2, j] > V1[k-1] & M2[2, j] <= V1[k])
> M3[i, k] = M3[i, k]+1
>
> }}}
Consider the following approach, which uses M2, V1 and V2 as
used in the code above.
V1 <- c(0, 10, 20, 30, 40)
V2 <- 1:3 # list of persons in the required order
M2 <- rbind(
c(1, 2, 1, 1, 3, 1, 3, 1),
c(11, 21, 21, 21, 11, 21, 11, 31))
person <- factor(M2[1, ], levels=V2)
interval <- cut(M2[2, ], breaks=V1)
M3 <- table(person, interval)
M2
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,]12113131
[2,] 11 21 21 21 11 21 11 31
M3
interval
person (0,10] (10,20] (20,30] (30,40]
1 0 1 3 1
2 0 0 1 0
3 0 2 0 0
Does this approach work for your data?
Petr Savicky.
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Re: [R] Counter
Try also: t( apply(x, 1, function(x) table( factor(x, levels = 0:2) ) ) ) # 0 1 2 # [1,] 1 2 1 # [2,] 1 3 0 # [3,] 3 0 1 # [4,] 0 2 2 See ?apply, ?table and ?factor for more details, examples and information. HTH, Jorge On Thu, Jul 23, 2009 at 6:44 AM, amor Gandhi wrote: > Hi everyone, > > Is there any counter function in R for the following purpose: > x <- matrix(c(1,1,0,2,1,0,0,2,0,1,2,1,2,1,0,1),nrow=4) > As I would like to know how many zeros, ones, and twos in each row of x? > > Many thank in advance, > Amor > > > > > >[[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. > > [[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.
Re: [R] Counter
On Thu, Jul 23, 2009 at 10:44:16AM +, amor Gandhi wrote: > Hi everyone, > > Is there any counter function in R for the following purpose: > x <- matrix(c(1,1,0,2,1,0,0,2,0,1,2,1,2,1,0,1),nrow=4) > As I would like to know how many zeros, ones, and twos in each row of x? Yes there is: As you are interested int he counts by row you can use apply: apply(x, 1, table) cu Philipp -- Dr. Philipp Pagel Lehrstuhl für Genomorientierte Bioinformatik Technische Universität München Wissenschaftszentrum Weihenstephan 85350 Freising, Germany http://webclu.bio.wzw.tum.de/~pagel/ __ 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.
Re: [R] Counter
apply(x, 1, table) Uwe Ligges amor Gandhi wrote: Hi everyone, Is there any counter function in R for the following purpose: x <- matrix(c(1,1,0,2,1,0,0,2,0,1,2,1,2,1,0,1),nrow=4) As I would like to know how many zeros, ones, and twos in each row of x? Many thank in advance, Amor [[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. __ 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.
