David Winsemius wrote: > Rainer M Krug <[EMAIL PROTECTED]> wrote in > news:[EMAIL PROTECTED]: > >> Hi >> >> I have some density estimates obtained from density(). I would like >> to calculate the sum of squares of these. As the x values of the >> estimates are not the same, and I would prefer not to restrict the >> estiomate to a certain range of x values, how can I do the >> calculation? >> >> Lets say: >> >> d1 <- density(Data1) >> d2 <- density(Data2) >> >> If the x values would be the same, I would: >> >> ssq <- sum( (d1$y - d2$y)^2 ) >> >> but as it isn't, I can't do that. >> >> is there an easy way to get the sum of squares? > > Presumably there is a common domain for these densities. Consider > forcing the x values to be the same by identically specifying n=, > from=, and to=?
Thanks - that's what I am doing right now and it is working > >> ?density >> x <- rnorm(200,1,1) >> x2 <- rnorm(200,1,1) >> d1 <- density(x, n=512, from=-1, to= 4) >> d2 <- density(x2, n=512, from=-1, to= 4) >> ssq <- sum( (d1$y - d2$y)^2 ) >> ssq > [1] 0.4722924 > >> x <- rnorm(200,1,1) >> x2 <- rnorm(200,1.5,1) >> d1 <- density(x, n=512, from=-1, to= 4) >> d2 <- density(x2, n=512, from=-1, to= 4) >> ssq <- sum( (d1$y - d2$y)^2 ) >> ssq > [1] 2.111498 > > ______________________________________________ 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.
