[R] sem with categorical data

I am trying to run a confirmatory factor analysis using the SEM package. My data are ordinal. I have read http://socserv.mcmaster.ca/jfox/Misc/sem/SEM-paper.pdf. When I apply the hetcor function, I receive the following error: Error in checkmvArgs(lower = lower, upper = upper, mean = mean, corr =

Re: [R] sem with categorical data

Dear Frank, Did you take a look at the data you generated? The contingency tables are extremely sparse. Try, e.g., with(dat, table(q1, q2)). (I assume, BTW, that you're using the cut2() function in the Hmisc package.) Beyond that, I'm not sure what the point is of your example. You're generating