Hello,
What is the best way to compute $R^2$ for endogenous variables in OpenMx?
I wrote the function below, I get negative $R^2$ for exogenous (not endogenous) variable. Shouldn't it produce zero for exogenous variables?
Thanks in advance,
Davood
r2sq <- function(model = NULL) { if (is.null(model)) stop("Please provide a model.") maniVar <- model@manifestVars df <- model@data@observed df <- df[maniVar] n <- nrow(df) S <- cov(df) res_mat <- model$S$values[maniVar, maniVar] R2 <- 1 - diag(res_mat) / diag(S) names(R2) <- maniVar return(R2) }