Dear friends. A very humble admirer of the progress of R with a very simple problem. I have the data shown below month day year dosis vanco 12 31 1999 1 3.8 1 3 2000 1 2.4 1 7 2000 1 3.4 1 12 2000 2 7.1 1 14 2000 2 5.3 1 17 2000 2 5.7 1 19 2000 3 7.7 1 21 2000 3 8.3 1 24 2000 4 8.7 1 26 2000 4 11.1 1 31 2000 4 12.3 2 7 2000 4.5 12.0 2 14 2000 4.5 14.9 2 18 2000 4.5 23.0 2 25 2000 3 20.1 2 28 2000 2 11.3 dates <- mdy.date(month,day,year) persp(dosis,dates,vanco) -- trying to produce a three demensional picture of vancomycin versus dose and data. but: Error in persp(dosis, dates, vanco) : increasing x and y values expected Dates is increaing, and I couldnot figure out how to make both dosis and dates increase and wonder how to produce a surface in this situation. Best regards Troels Ring, M.D Department of Nephrology Aalborg, Denmark tring at mail1.stofanet.dk -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._