Dear Bryan, There are a few problems below: 1) You extract and recode each variable independently. You need to recode them in the context of the data frame to preserve the indexing of each variable against every other variable. When you use as.ordered(), you need to check to make sure that R is putting the factors in the order that you want them to be in. And I think you want as.factor() -- which creates unordered factors -- rather than as.ordered(). R treats an ordered factor as a helmert contrast matrix, and I think you just want matricies of indicator variables for each of the factors. 2) The statement to run zelig is a bit confusing. Every argument except for the first requires a label, and you are specifying some arguments which are not necessary at all. Try instead: ethdata <- na.omit(ethdata) z.out <- zelig(meadd ~ q11 + q255 + ecinteg + q89 + q87 + q4 + ethnicp + q66 + q94 + neighb, model = "ologit", data=ethdata) 3) I never attach() my data. R will get confused between variables in the attached data frame and variables in the workspace of the same name. Hope this helps! Olivia Lau ----- Original Message ----- From: Bryan Williams To: zelig(a)latte.harvard.edu Sent: Tuesday, November 30, 2004 7:16 AM Subject: [zelig] Zelig Help: invalid subscript error when invoking "ologit" I'm trying to do an ordered logistic regression and then generate first differences, however I've run up against an "invalid subscript error" that I can't figure out. I would sincerely appreciate any help you could give me on this. My data looks like this: q4 q11 q255 q66 q87 q89 q94 ethnicp ecinteg neighb 1 3 1 2 0 53 4 2 -1.11010 8 2 2 2 1 3 0 58 4 2 0.42035 8 2 3 3 1 3 0 56 4 2 -0.56365 8 2 4 2 1 3 0 75 3 2 -1.13594 6 2 5 4 1 2 0 51 4 2 -2.28052 7 2 6 3 1 3 0 33 4 2 1.13252 7 2 7 2 1 2 0 <NA> 4 2 1.13252 8 1 8 1 0 0 0 <NA> 4 2 0.14851 5 2 (the left-most numbers are the automatically assigned row numbers) And my commands look like (please remember that I'm new to R so my procedure may look a bit sloppy): #Load the sample data: ethdata.r<-read.spss("C:/Documents and Settings/Bryan Williams/My Documents/ethnicity paper/ethdata.r.sav", to.data.frame=T) attach(ethdata.r) # OR IF LOADED ALREADY: >data(ethdata.r) #Create ordered dependent & independent variables: meadd<- as.ordered (MEADD) ecinteg <- as.ordered(ECINTEG) ethnicp <- as.numeric(ETHNICP) q4 <- as.ordered(Q4) q11 <- as.ordered(Q11) q66 <- as.ordered(Q66) q89 <- as.ordered(Q89) q87 <- as.ordered(Q87) q94 <- as.ordered(Q94) q255 <- as.ordered(Q255) neighb <- as.ordered(NEIGHB) rm(ethdata.r) ethdata<-data.frame(q4,q11,q255,q66,q87,q89,q94,ethnicp,ecinteg,neighb) attach(ethdata) #Estimate the model*******THIS IS THE PROBLEMATIC LINE-I've used "options(error=recover) to step through the equation, but don't understand what goes wrong: "[.data.frame",,by : invalid subscript type ********************************************************************** z.out <- zelig(meadd ~ q11 + q255 + ecinteg + q89 + q87 + q4 + ethnicp + q66 + q94 + neighb , weight=WT, start=0, na.exclude(ethdata), model = "ologit", data=ethdata) #it never gets to the following line summary(z.out) Thank you for your consideration, Bryan Williams Doctoral Candidate Department of Political Science University of Florida chakabry(a)ufl.edu (352)392-0262 x290 - Zelig Mailing List, served by Harvard-MIT Data Center Send messages: zelig(a)latte.harvard.edu [un]subscribe Options: http://lists.hmdc.harvard.edu/?info=zelig Zelig program information: http://gking.harvard.edu/zelig/