From: Dimitris Rizopoulos <dimitris.rizopoulos_at_med.kuleuven.ac.be>

Date: Mon 26 Jul 2004 - 18:59:34 EST

Dimitris Rizopoulos

Doctoral Student

Biostatistical Centre

School of Public Health

Catholic University of Leuven

R-help@stat.math.ethz.ch mailing list

https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Mon Jul 26 19:11:18 2004

Date: Mon 26 Jul 2004 - 18:59:34 EST

Hi Stefan,

you could try something like,

x <- c(2,4,7)

as.numeric(!is.na(match(seq(1, max(x)), x)))

I hope this helps.

Best,

Dimitris

Dimitris Rizopoulos

Doctoral Student

Biostatistical Centre

School of Public Health

Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium

Tel: +32/16/396887 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm

- Original Message ----- From: "Stefan Böhringer" <commercial@s-boehringer.de> To: "R Help" <r-help@stat.math.ethz.ch> Sent: Monday, July 26, 2004 10:45 AM Subject: [R] computing sum of indicator variables

> My problem is as follows:

*> i is a list of integers of variable length. Now I want to compute a
*

new

> vector/array that contains 1's at the positions indicated in i. For

*> example:
**> c(2, 4) -> c(0, 1, 0, 1)
**>
**> Using something like
**> i = i - c(0, i[2:length(i) - 1]);
**> sapply(i, function(x) c(rep(0, x - 1), 1)));
**>
**> faces me with the problem of concatenating the result, which I could
**> somehow not find a solution for.
**>
**> Thank you very much in advance.
**>
**> Stefan
**>
**> ______________________________________________
**> R-help@stat.math.ethz.ch mailing list
**> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
**> PLEASE do read the posting guide!
*

http://www.R-project.org/posting-guide.html

R-help@stat.math.ethz.ch mailing list

https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Mon Jul 26 19:11:18 2004

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