Hi all, Does anybody have a hint on what may be going wrong in this R code? I mimic the sample code from the MNP developers but I seem unable to get the choice specific variables right.
Thanks, Joan Serra > rm(list=ls()) > library(foreign) > small<-read.spss("small.sav") Warning message: small.sav: Unrecognized record type 7, subtype 13 encountered in system file. > library(MNP) MNP: R Package for Fitting the Multinomial Probit Models Version: 1.3-1 URL: http://www.princeton.edu/~kimai/research/MNP.html > > res1 <- mnp(PREVOTE3 ~ 1, choiceX = list(1=UCLC, 2=UDLC, 3=UPLC), Error: syntax error > cXnames = "ut", data = small, n.draws = 500, burnin = 100, Error: syntax error > verbose = TRUE) Error: syntax error > > # another try giving arbitrary names to the values of the dependent variable > > res1 <- mnp(PREVOTE3 ~ 1, choiceX = list(Clinton=UCLC, Dole=UDLC, Perot=UPLC), + cXnames = "ut", data = small, n.draws = 500, burnin = 100, + verbose = TRUE) The base category is `1'. The total number of alternatives is 3. Error in xmatrix.mnp(formula, data = eval.parent(data), choiceX = call$choiceX, : Error: Invalid input for `choiceX.' Some variables do not exist. > > # another try using a string type dependent variable > > res1 <- mnp(PRVOTE3 ~ 1, choiceX = list(Clinton=UCLC, Dole=UDLC, Perot=UPLC), + cXnames = "ut", data = small, n.draws = 500, burnin = 100, + verbose = TRUE) Error in model.frame(formula, rownames, variables, varnames, extras, extranames, : invalid variable type > ______________________________________________ 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