从 lavaan 中提取误差协方差矩阵

如何解决从 lavaan 中提取误差协方差矩阵

我想从 sem() 中提取误差协方差矩阵，但我不知道我是否做对了。我使用了 inspect("cov.ov")，对于 "cov.ov"，文档说“模型隐含的方差-协方差矩阵”。那么这与误差协方差矩阵相同吗？代码如下：

# convert vector of correlations into matrix
   wisc4.cor <- lav_matrix_lower2full(c(1,0.72,1,0.64,0.63,0.51,0.48,0.37,0.38,1))
# enter the SDs
   wisc4.sd <- c(3.01,3.03,2.99,2.89,2.98)
# name the variables
   colnames(wisc4.cor) <- rownames(wisc4.cor) <- c("Information","Similarities","Word.Reasoning","Matrix.Reasoning","Picture.Concepts")
   names(wisc4.sd) <-  c("Information","Picture.Concepts")
# convert correlations and SDs to covarainces
   wisc4.cov <- cor2cov(wisc4.cor,wisc4.sd)
# specify single factor model
   wisc4.model<-'
   g =~ a*Information + b*Similarities + c*Word.Reasoning + d*Matrix.Reasoning + e*Picture.Concepts
'
# fit model
   wisc4.fit <- sem(model=wisc4.model,sample.cov=wisc4.cov,sample.nobs=550,std.lv=FALSE)
#does this extract the error covariance matrix?
   inspect(wisc4.fit,"cov.ov")

解决方法

你想要残差的 cov 矩阵：

residuals(wisc4.fit)$cov