search for: readmoment

Hi there, I searched R-help list with "path analysis" as keyword, and learn that sem package can do it. However, I don't figure out a way to construct the model for the path diagram as Fig. 1. in Huang et al. (2002)[1]. I try the following code: huang.cor <- readMoments(diag=FALSE, names=c('x1', 'x2', 'x3', 'y')) 0.76 0.91 0.72 0.94 0.77 0.83 huang.mod <- specifyModel() x1 -> y, p1 x2 -> y, p2 x3 -> y, p3 x1 -> x2, p12 x2 -> x1, p21 x2 -> x3, p23 x3 -> x2, p32 x1 -> x3, p13 x3 -> x1, p31 huang.sem &l...

Hello I am using sem to look at the direct effect of one variable on another but i am uncertain if i am progressing correctly. An example: covar1<-? matrix(c(0.4,-0.2,3,-0.2 , 0.3,-2 , 3 ,-2 , 60), nrow=3,byrow=T) rownames(covar1)<-colnames(covar1)<-c("endo","exo","med") path1<-matrix(c(? ? "exo -> endo",? "g1", NA,