search for: groupmean

...ead.table("P:\\Transit\\CORRECT files\\Everything-newest.csv",header=T, sep=",", dec=".", na.strings=NA, strip.white=T) vcdf<-data.frame(vc) tempdf<-data.frame(cbind(vcdf[,1:3], vcdf[,429])) newtemp<-na.exclude(tempdf) newtemp[,2]<-factor(newtemp[,2]) groupmean<-tapply(newtemp[,4], newtemp[,2], mean) newmark<-factor(groupmean, exclude=(groupmean==0 | groupmean==1)) newmark This is what the output is (going up to 61 levels) 1 2 3 4 <NA> 0.142857142857143 0.444444444444444 <...

...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 level of GROUP, but i cannot find out, how to give every person the groupmean as a value (every person should have the same value as every other person in the same group). Has anybody any ideas how to do that ? Yours sincerly Felix Eschenburg

...here must be a simple way to get the within group pooled covariance matrix but I haven't found it yet. I started thinking that one might begin by forming a frame with the same dimensions but containing the group means. But then I found a thread from two years back called "Getting the groupmean for each person" which seemed to imply that doing this was a bit subtle even for ncol=1. Hence I will risk a question to the list. Thanks for any help, Murray Jorgensen -- Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waika...

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.