R community, My question is a bit complex to explain (and consequently difficult to search for in the archives). I will illustrate it with a simplified example.
If I have an array of sample sizes for various factor levels, of all different sizes (due to missing data), and another array of those same factor levels' means, and I would like to sum the squares and weight them with their corresponding sample size as such: ss <- sum( n*(yi.bar - y..bar)^2) [note that y..bar is not an array] Will R parse the array n at the same rate as it is yi.bar (an equally long array of the means of those n samples)? Note that I am more sure of using something like: x <- c(data...) ss <- sum(length(na.exclude(x))*(mean(na.exclude(x)) - y..bar)^2) But alas, there are cases when only the means and the sample sizes are supplied, but not the actual data. I would also like to stray away from using built-in functions (weighted.mean perhaps?) do gain an understanding of how this would be done. Thank you! Vince -- "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." -Bertrand Russell ______________________________________________ [email protected] 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.
