search for: groupmeans

...any times as there are elements in the group for which each is calculated. So for E.g. if level 1 of newtemp[,2] has about 15 elements, <NA> should be printed 15 times, level 2 = 12 times 0.1428, and so on. Is there a way of specifying that a list needs to be populated with replicates of groupmeans based on values got from newtemp[,2]? I just can't seem to figure this out by myself. Many thanks for your help. Aditi ---------------------- A Singh Aditi.Singh at bristol.ac.uk School of Biological Sciences University of Bristol

Hello list ! I have a huge data.frame with several variables observed on about 3000 persons. For every person (row) there is variable called GROUP which indices the group the person belongs to. There is also another variable AV for each person. Now i want to create a new variable which holds the group mean of AV as a value for each person. With tapply(AV,GROUP,mean) i get the means for each

I am in a discriminant analysis situation with a frame containing several variables and a grouping factor, if you like: set.seed(200906) exampledf <- as.data.frame(matrix(rnorm(50,5,2),nrow=10,ncol=5)) exampledf$Group <- factor(rep(c(1,2,3),c(3,3,4))) exampledf I'm sure there must be a simple way to get the within group pooled covariance matrix but I haven't found it yet. I

From: David Winsemius <dwinsemius at comcast.net> On Jul 16, 2011, at 12:15 PM, Rory Campbell-Lange wrote: > On 16/07/11, David Winsemius (dwinsemius at comcast.net) wrote: >> >> On Jul 16, 2011, at 11:19 AM, Rory Campbell-Lange wrote: >> >>> I'm an R beginner, and I would like to construct a set of boxplots >>> showing database function runtimes.

Hi, Currently, the "base" has colSums, colMeans. It seems that it would be useful to extend this to also include colMin, colMax (of course, rowMin and rowMax, as well) in order to facilitate faster computations for large vectors (compared to using apply). Has this been considered before? Please forgive me if this has already been discussed before. Thanks, Ravi Ravi Varadhan, Ph.D.