Joaquin (Kino) Aguilar
2012-Aug-08 19:46 UTC
[R] Testing for a second order factor using SEM package
Hi! The following model specification works when testing for first order factors, but when I attempt to test for a second order factor by adding the last 4 lines in the model, I get the error message below: model.cfa.ru <- specifyModel() sRU1 <- sRU, NA, 1 sRU2 <- sRU, lam12 sRU3 <- sRU, lam13 sRU4 <- sRU, lam14 sRU5 <- sRU, lam15 sRU6 <- sRU, lam16 sRU <-> sRU, mak1 sRU1 <-> sRU2, cors1 sRU5 <-> sRU3, cors2 sRU6 <-> sRU2, cors3 sRU6 <-> sRU1, cors4 pRU1 <- pRU, sfsf pRU2 <- pRU, lam22 pRU3 <- pRU, lam23 pRU4 <- pRU, lam24 pRU5 <- pRU, lam25 pRU6 <- pRU, lam26 pRU <-> pRU, mak1 pRU5 <-> pRU3, corp1 pRU4 <-> pRU6, corp2 pRU5 <-> pRU6, corp3 pRU6 <-> pRU2, corp4 rRU1 <- rRU, sdfsdf rRU2 <- rRU, lam32 rRU3 <- rRU, lam33 rRU4 <- rRU, lam34 rRU5 <- rRU, lam35 rRU6 <- rRU, lam36 rRU7 <- rRU, lam37 rRU8 <- rRU, lam38 rRU <-> rRU, mak1 rRU3 <-> rRU1, corr1 rRU7 <-> rRU4, corr2 rRU8 <-> rRU7, corr3 rRU8 <-> rRU2, corr4 rRU5 <-> rRU2, corr5 rRU7 <-> rRU5, corr6 rRU8 <-> rRU5, corr7 sRU <-> pRU, tmp1 sRU <-> rRU, tmp2 pRU <-> rRU, tmp3 sRU <- sof, lok1 pRU <- sof, lok2 rRU <- sof, lok3 sof <-> sof, lok4 cfa.ru <- sem(model.cfa.ru, data=ru) Error in w_mat %*% p_deriv_mat %*% invMat : requires numeric/complex matrix/vector arguments In addition: Warning message: In eval(expr, envir, enclos) : Negative parameter variances. Model may be underidentified. I've done a number of modifications to the model specification with no success. I'm wondering if I'm missing something? Thank you! [[alternative HTML version deleted]]