[R] computing sum of indicator variables

From: Stefan Böhringer <commercial_at_s-boehringer.de>
Date: Mon 26 Jul 2004 - 18:45:52 EST


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



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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 18:52:42 2004

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