Hello all,
I'm trying to run a CFA with ordinal and binary indicators. When I run the following code...
AlcMark_M1_CFA <- cfa(AlcMark_M1, data = Kampala, estimator = "PML",missing="doubly.robust",test="none",
parameterization="theta", ordered=c("Q7_LFZRc","Q9_LZRc","Q12_LFZRc","Q13_X_LFZRc","Q15_LFZRcRv","Q16_X_LFRc","Q17_LFRc","Q18a_LF","Q18b_LF","Q18c_LF","Q86j_LF"))
...I get this error message:
Error in nlminb(start = cache$theta, objective = minObjective, gradient = minGradient, :
NA/NaN Hessian evaluation
I get the same message when I estimate with WLSMV, or change missing to using "listwise", "pairwise", or "available.cases".
I have tried running the model with and without manifest covariances that could account for some potential autocorrelation between variables, without any change.
I have tried running with both Lavaan 0.6-6 and the current dev version, without any change.
I have tried both theta and delta parameterization, as well as not specifying the parameterization.
I cannot find any explanation of what "NA/NaN Hessian evaluation" means, and I am having trouble understanding the rest of the error message.
Any ideas?