> data1 <- expand.grid(var1=1:15, var2=1:2) > test <- replicate(1000, with(data.frame(var1=data1$var1, > var2=sample(data1$var2)), diff(tapply(var1, var2, mean)))) > hist(test) ------------------------------------------------------------------- Jacques VESLOT
CNRS UMR 8090 I.B.L (2ème étage) 1 rue du Professeur Calmette B.P. 245 59019 Lille Cedex Tel : 33 (0)3.20.87.10.44 Fax : 33 (0)3.20.87.10.31 http://www-good.ibl.fr ------------------------------------------------------------------- Jacob van Wyk a écrit : > Hallo > > Is there an elegant way to do the following: > > Dataset consists of 2 variables: var1: some measurements, and var2: a > grouping variable with two values, 1 and 2. > There are (say) 10 measurements from group 1 and 15 measurements from group 2. > The idea is to study the permutation distribution of mean(group 1) * > mean(group2). > One way would be to permute 1s and 2s and select the corresponding > measurements; calculate the difference in means. > Redo this 1000 times, say. Etc. > > Any help is much appreciated. > Thanks > Jacob > > > Jacob L van Wyk > Department of Statistics > University of Johannesburg, APK > P O Box 524 > Auckland Park 2006 > South Africa > Tel: +27 11 489 3080 > Fax: +27 11 489 2832 > > > > [[alternative HTML version deleted]] > > ______________________________________________ > [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. > ______________________________________________ [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.
