> x <- 1:5
> length(x) <- 2 ^ ceiling(log(length(x))/log(2))
> x
[1] 1 2 3 4 5 NA NA NA
>
However, one needs to be careful with kind of arithmetic -- floating point inaccuracies can cause unexpected results. E.g., one would expect the following points to form a straight line, but they don't -- on my computer there are 4 anomalies between 29 and 50:
> plot(ceiling(log(2**(1:50))/log(2)))
In the question asked, this is unlikely to cause problems as it is unlikely that a vector will have 2^29 elements.
At Friday 09:51 AM 2/14/2003 +0000, Poizot Emmanuel wrote:
Hi, I would like to know if there is a way to change a vector of arbitrary size to make it fits the nearest upper size multiple of a power of 2.-- Cordialy ---------------------------------------- Emmanuel POIZOT Cnam/Intechmer Digue de Collignon 50110 Tourlaville T�l : (33)(0)2 33 88 73 42 Fax : (33)(0)2 33 88 73 39 ----------------------------------------- ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
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