Hi: On Mon, Feb 28, 2011 at 8:42 AM, John Sorkin <jsor...@grecc.umaryland.edu>wrote:
> R 2.10.0 > Windows XP > > I am trying to run lme. I receive the following error message: > My lme code is: > fitRandom <- lme(values ~ factor(subject), > data=withindata) > Where's the random factor? Perhaps you mean lme(values ~ 1, random = ~ 1 | subject, data = withindata) or in lme4, lmer(values ~ 1 + (1 | subject), data = withindata) HTH, Dennis PS: Use of dput() output is more helpful than copying from the console, as it retains the same classes you have on your end. > dput(withindata) structure(list(subject = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), values = c(2.3199639, -8.5795802, -4.1901241, 0.4588128, 16.9128232, 8.9856358, 1.9303254, -1.4320313, -15.4225123, 5.9293529, -29.2014153, -8.9684986, -11.906217, 13.2133887, 1.2491941, -8.0613768, -5.6340179, 3.1916857, -7.7447932, 2.2316354, 0.6444938, 4.6912677, 20.9135073, 2.1433533, -0.8057022, -13.0187979, 8.9634065, 13.4815344, 4.6148061, -18.4781373, 15.5263564, -2.1993412, 5.183026, 16.2311097, -2.5781897, -3.016729, -0.1119353, 1.1983126, -8.8212143, 3.8895263)), .Names = c("subject", "values"), class = "data.frame", row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40")) Below I have printed the console output, and at the bottom of this message, > I have printed my code. > I hope someone can tell my what I am doing wrong. > Thank you, > John > > > print(withindata) > subject values > 1 1 2.3199639 > 2 1 -8.5795802 > 3 1 -4.1901241 > 4 1 0.4588128 > 5 1 16.9128232 > 6 1 8.9856358 > 7 1 1.9303254 > 8 1 -1.4320313 > 9 1 -15.4225123 > 10 1 5.9293529 > 11 2 -29.2014153 > 12 2 -8.9684986 > 13 2 -11.9062170 > 14 2 13.2133887 > 15 2 1.2491941 > 16 2 -8.0613768 > 17 2 -5.6340179 > 18 2 3.1916857 > 19 2 -7.7447932 > 20 2 2.2316354 > 21 3 0.6444938 > 22 3 4.6912677 > 23 3 20.9135073 > 24 3 2.1433533 > 25 3 -0.8057022 > 26 3 -13.0187979 > 27 3 8.9634065 > 28 3 13.4815344 > 29 3 4.6148061 > 30 3 -18.4781373 > 31 4 15.5263564 > 32 4 -2.1993412 > 33 4 5.1830260 > 34 4 16.2311097 > 35 4 -2.5781897 > 36 4 -3.0167290 > 37 4 -0.1119353 > 38 4 1.1983126 > 39 4 -8.8212143 > 40 4 3.8895263 > > fitRandom <- lme(values ~ factor(subject), > + data=withindata) > Error in getGroups.data.frame(dataMix, groups) : > Invalid formula for groups > > summary(fitRandom) > Error in summary(fitRandom) : object 'fitRandom' not found > > > > My code: > > library(nlme) > > # Define essential constants. > # Number of subject studied. > NSubs <- 4 > # Number of observations per subject. > NObs <- 10 > # Between study SD > tau <- 4 > # Within study SD. > sigma <- 8 > # END Define essential constants. > > # Define between subject variation > between <- matrix(nrow=10,ncol=1) > between <- rnorm(NSubs,0,tau) > between > # END Define between subject variation. > > # Define within subject varation. > within <- matrix(nrow=NObs*NSubs,ncol=2) > for (subject in 1:NSubs) { > # Create a variable defining subject. > within[c(1:NObs)+((subject-1)*NObs),1] <- subject > # Create within subject variation. > within[c(1:NObs)+((subject-1)*NObs),2] <- > rnorm(NObs,between[subject],sigma) > } > # END Define within subject variation. > > # Create a dataframe to hold values. > withindata <- data.frame(subject=within[,1],values=within[,2]) > print(withindata[1:4,]) > > print(withindata) > fitRandom <- lme(values ~ subject, > data=withindata) > summary(fitRandom) > > > > John David Sorkin M.D., Ph.D. > Chief, Biostatistics and Informatics > University of Maryland School of Medicine Division of Gerontology > Baltimore VA Medical Center > 10 North Greene Street > GRECC (BT/18/GR) > Baltimore, MD 21201-1524 > (Phone) 410-605-7119 > (Fax) 410-605-7913 (Please call phone number above prior to faxing) > > Confidentiality Statement: > This email message, including any attachments, is for ...{{dropped:13}} ______________________________________________ R-help@r-project.org 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.