semTools::measEq.syntax - Error: no method for coercing this S4 class to a vector

[cla...@googlemail.com]

Hi,

I am working on measurement invariance analysis using semTools to create syntax for multi-group CFA with categorical indicators (MI across biological sex, 2 groups).

I have been using the very useful measEq.syntax-function until now. However. since beginning of March I cannot execute my syntax anymore.  I have tried a lot of troubleshooting options (see below) - none worked.

Here is example code and exemplary error presentation:

 fit <- measEq.syntax(configural.model = mod.cat, data = df_mi_parent,
                            ordered = c("item1", "item2", "item3", ...., "item25"),
                            group = "sex",group.label=c("1", "2"),
                            estimator ="DWLS",
                            test = "scaled.shifted",
                            se = "robust",
                            parameterization = "theta",
                            ID.fac = "std.lv", ID.cat = "Wu.Estabrook.2016",
                            group.equal = "thresholds")

# Runs perfectly

summary(syntax.thresh)                    # summarize model features

Length Class Mode 1 measEq.syntax S4

mod.thresh <- as.character(syntax.thresh) # save as text

Error in as.character.default(syntax.thresh) : no method for coercing this S4 class to a vector

cat(mod.thresh)  # print/view lavaan syntax

# cannot be executed since line above was aborted.

I have attempted the following troubleshooting approaches. Unfirtunately, all have been  unsuccessful.

1. updated R, lavaan and semTools

2. Followed this: https://stackoverflow.com/questions/63065696/error-in-getmethodsummary-signature-fitdiff/63600180#63600180

3. also tried this, loading semTools (not loading lavaan first etc.): https://github.com/simsem/semTools/issues/116

4. Rerun all following this example: https://www.rdocumentation.org/packages/semTools/versions/0.5-6/topics/measEq.syntax

I would highly appreciate some help on how to overcome the S4 issue. I am not an R-programmer and therefore have a limited understanding of the S3/S4 classesd/objects. I am an applied researcher - Hence, I appreciate any help I solve the issue using semTools or any workaround.

Thanks in advance, I am happy to provide more information or code and hope this follows the community guidelines.

Best

Claudia

[Terrence Jorgensen]

Your example is not complete, so it is difficult to diagnose anything without a full reprex.  Your issues are about an object "syntax.thresh", which is not created in the syntax you posted (instead, an object "fit" is created).

Terrence D. Jorgensen    (he, him, his)
Assistant Professor, Methods and Statistics
Research Institute for Child Development and Education, the University of Amsterdam
http://www.uva.nl/profile/t.d.jorgensen