Dear list I am using the 'geese' command in the geepack Package add-on to R. I am wanting to define my own correlation matrix for 4 time occasions such that there is correlation between times 1&2, 1&3, 2&4 and 3&4 but not 1&4 and 2&3. There is an option to define a design matrix called zcorr. Could anyone tell me how I can create this design matrix such that it will show the correlations that I need to include? Many thanks Laura -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._