My apologies: you need an abs() call as well: which(abs(outer(x, y, "-")) < threshold, arr.ind = TRUE)
Michael On Sun, Dec 4, 2011 at 6:25 PM, R. Michael Weylandt <michael.weyla...@gmail.com> wrote: > Not sure what to make of the fact that your x, y are of different > lengths: if you mean to check all possible pairings, this is probably > what you need: > > which(outer(x, y, "-") < threshold, arr.ind = TRUE) > > Michael > > On Sun, Dec 4, 2011 at 2:24 PM, andrija djurovic <djandr...@gmail.com> wrote: >> Hi. Maybe this can help you (you can try additionally to incorporate >> threshold): >> >>> set.seed(1) >>> x<-rnorm(10,10,1) >>> values <- sample(1:10,10) #values that we are looking for >>> mat <- matrix(c(x,values),ncol=2) >>> >>> closest<-function(x,values) #function is an example from The R book >> (Crawley) >> + { >> + x[which(abs(x-values)==min(abs(x-values)))] >> + } >>> >>> apply(mat[,2,drop=FALSE],1,function(y) closest(mat[,1],y)) >> [1] 10.183643 9.164371 9.164371 9.164371 9.164371 9.164371 9.164371 >> 9.164371 >> [9] 9.164371 9.164371 >> >> >> On Sun, Dec 4, 2011 at 7:00 PM, vamshi999 <vamshi...@gmail.com> wrote: >> >>> Hello List, >>> >>> I am having trouble finding the command for my problem. >>> >>> I have two arrays x and y. now i would like to compare the values of x and >>> y >>> and then get the index of x which is exactly or approximately equal(+/- >>> some >>> value ) to the values in y. >>> x <- runif(100,min=0,max=5) >>> y <- runif(10,min=0,max=5) >>> >>> >>> the threshold value(+/-) value can vary. for this example lets take it to >>> be >>> .5 >>> >>> I know the regular method of doing this by writing different if and for >>> loops. But i have very big dataframe the computation time is very high for >>> this method. can anyone please tell me if there any functions to do this. >>> >>> thank you for your help. >>> >>> -- >>> View this message in context: >>> http://r.789695.n4.nabble.com/equating-approximate-values-tp4157551p4157551.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. >>> >> >> [[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.