R/ctr_modelcov.R

In nietsnel/psindex: Parameter Stability Index

# takes a model in psindex syntax and the user's data and returns the covariance
# matrix of observed variables.  Useful so that the user can do things like
# diagnose errors in the cov matrix, use cov2cor to look at the correlation
# matrix, try and invert the sample covariance matrix, etc.

# update 5/27/2011 JEB
# changelog: using sem and inspect to get output.  
#            This way, all arguments such as groups, etc, can be used
# update 3 june 2011 YR: removed se="none" (since now implied by do.fit=FALSE)
# update 13 dec 2011 YR: changed name (to avoid confusion with the 
#                        model-implied cov)
inspectSampleCov <- function(model, data, ...) {
    fit <- sem(model, data=data, ..., do.fit=FALSE)
    inspect(fit, "sampstat")
}