Re: [R] give all combinations

From: ONKELINX, Thierry <>
Date: Mon, 01 Sep 2008 10:12:41 +0200

A more generic solution is

allComb <- expand.grid(rep(list(letters[1:5]), 7)) whichComb <- sapply(seq_len(ncol(allComb) - 1), x = allComb, function(i, x){

    whichCombination <- sapply(seq(i + 1, ncol(x)), y = x, function(j, y){

        as.numeric(y[, i]) <= as.numeric(y[, j])     })
    apply(whichCombination, 1, all)
allComb[apply(whichComb, 1, all), ]

HTH, Thierry

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance
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tel. + 32 54/436 185

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The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data.
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-----Oorspronkelijk bericht-----
Van: [] Namens Lucien Lemmens
Verzonden: zondag 31 augustus 2008 15:58 Aan:
Onderwerp: Re: [R] give all combinations

Another solution requiring also a bit of programming is:

 for(i in 1:3){c2<-c(c2,paste(letters[i],letters[i:3],sep=""))}  c2
[1] "aa" "ab" "ac" "bb" "bc" "cc"
 c3<-c();for(i in
1:n){c3<-c(c3,paste(c2[i],letters[ceiling(i/2):3],sep=""))}  c3
 [1] "aaa" "aab" "aac" "aba" "abb" "abc" "acb" "acc" "bbb" "bbc" "bcc" "ccc" mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code.

Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Mon 01 Sep 2008 - 08:15:11 GMT

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