Could someone help me understand this Basically I want to know the position of certain numbers in large output data sets. First consider the following simple example where we get the postions of ones (1) in the vector q.
> q <- c(5,1,1,3,1,1,1,1) > q [1] 5 1 1 3 1 1 1 1 > for (i in 1:length(q)) if(q[i]==1) print(i) [1] 2 [1] 3 [1] 5 [1] 6 [1] 7 [1] 8 Well done! But now consider the following case where the input consists of different combinations of the three numbers 2, 3 and 7. They are put into a function 1/x +1/y +1/z +1/(x*y*z). All different combinations will yield the same result namely precisely 1, which is also clearly seen in the output. However when I try to get information on the position of the ones in the output, there are only two that are recognized, although all six items in the output are indeed ones. > x <- c(2,2,3,3,7,7); y <- c(3,7,2,7,2,3); z <- c(7,3,7,2,3,2) > data.frame(x,y,z) x y z 1 2 3 7 2 2 7 3 3 3 2 7 4 3 7 2 5 7 2 3 6 7 3 2 > p <- numeric(length(x)) > for (i in 1:length(x)) p[i] <- ((1/x[i]) + (1/y[i]) + (1/z[i]) + (1/(x[i]*y[i]*z[i]))) > p [1] 1 1 1 1 1 1 > for (i in 1:length(p)) if(p[i]==1) print(i) [1] 4 [1] 6 I suppose there must exist some better way of accessing the position of certain numbers in a large data output. So apart from getting advice on that I would certainly also like to understand why the above only seems to work in some cases. Anders B Falk PhD Uppsala Sweden ______________________________________________ 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.
