Hi, the following R lines work fine in R 2.4.0, but not in R 2.4.1 or any devel versions of R 2.5.0 (see below for details).
library(drc) # to load the dataset 'PestSci' library(nlme) ## Setting starting values sv <- c(0.43355869, 2.49963220, 0.05861799, 1.73290589, 0.38153146, 0.24316978) ## No error m1 <- nlme(SLOPE ~ c + (d-c)/(1+exp(b*(log(DOSE)-log(e)))), fixed = list(b+c+d+e~1), random = d~1|CURVE, start = sv[c(2:5)], data = PestSci) ## No error m2 <- nlme(SLOPE ~ c + (d-c)/(1+exp(b*(log(DOSE)-log(e)))), fixed = list(b~HERBICIDE, c+d+e~1), random = d~1|CURVE, start = sv[c(1:5)], data = PestSci) ## Error in R 2.4.1! m3 <- nlme(SLOPE ~ c + (d-c)/(1+exp(b*(log(DOSE)-log(e)))), fixed = list(b~factor(HERBICIDE)-1, c~1, d~1, e~factor(HERBICIDE)-1), random = d~1|CURVE, start = sv, data = PestSci) Error in dimnames(data) <- dimnames : length of 'dimnames' [1] not equal to array extent An ensuing call to traceback() yields: 7: array(0, c(n, n), list(levs, levs)) 6: contr.treatment(n = 0) 5: do.call(contr[[nm]], list(n = length(levs))) 4: FUN("factor(HERBICIDE)"[[1]], ...) 3: lapply(nms, contrMat, contr = contr, data = dataMix) 2: nlme.formula(SLOPE ~ c + (d - c)/(1 + exp(b * (log(DOSE) - log(e)))), fixed = list(b ~ factor(HERBICIDE) - 1, c ~ 1, d ~ 1, e ~ factor(HERBICIDE) - 1), random = d ~ 1 | CURVE, start = sv, data = PestSci) 1: nlme(SLOPE ~ c + (d - c)/(1 + exp(b * (log(DOSE) - log(e)))), fixed = list(b ~ factor(HERBICIDE) - 1, c ~ 1, d ~ 1, e ~ factor(HERBICIDE) - 1), random = d ~ 1 | CURVE, start = sv, data = PestSci) Output from sessionInfo() for R 2.4.0 R version 2.4.0 (2006-10-03) i386-pc-mingw32 locale: LC_COLLATE=Danish_Denmark.1252;LC_CTYPE=Danish_Denmark.1252;LC_MONETARY=Danish_Denmark.1252;LC_NUMERIC=C;LC_TIME=Danish_Denmark.1252 attached base packages: [1] "methods" "stats" "graphics" "grDevices" "utils" "datasets" [7] "base" other attached packages: drc plotrix nlme MASS lattice "1.0-7" "2.1-1" "3.1-77" "7.2-29" "0.14-9" Output from sessionInfo() for R 2.4.1 R version 2.4.1 (2006-12-18) i386-pc-mingw32 locale: LC_COLLATE=Danish_Denmark.1252;LC_CTYPE=Danish_Denmark.1252;LC_MONETARY=Danish_Denmark.1252;LC_NUMERIC=C;LC_TIME=Danish_Denmark.1252 attached base packages: [1] "stats" "graphics" "grDevices" "utils" [5] "datasets" "methods" "base" other attached packages: drc plotrix nlme MASS lattice "1.0-7" "2.1-6" "3.1-78" "7.2-30" "0.14-16" Christian ______________________________________________ R-help@stat.math.ethz.ch 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.