02-27-2014 01:02 AM
i want to estimate parameters of sem by using weighted least square method but i have some question through the following sas program:
1- i want to write my own weight matrix how??
2- how can i write initial values?
3- how can i change link function here?
proc calis nobs=1000 data=MVO method=WLS;
X1 = a1*F1+e1,
X2 = F1+e2,
X3 = F1+e3,
X4 = F1+e4,
X5 = a5*F2+e5,
X6 = F2+e6,
X7 = a7*F3+e7,
X8 = F3+e8,
X9 = a9*F4+e9,
X10 = F4+e10,
F2 = F1+d1,
F3 = F1+d2;
e1-e10 = The1-The10,
d1-d2 = psi1-psi2;
e3 e5 = The11,
e4 e6 = The12;
thanks in advance
02-27-2014 09:42 AM
The documentation for CALIS lays these out fairly clearly (and I would NEVER say that I am an expert in PROC CALIS).
1. In the PROC CALIS statement, use INWGT= to input the weight matrix.
2. In the PARAMETERS statement, initial values can be specified in parenthesis after the parameter name, for example: a1 (0.2), if you wanted an initial value of 0.2 for parameter a1.
3. There is no link function in PROC CALIS.
02-28-2014 09:29 AM
thanks alot mr. denham
i want to use categorical data with SEM then i must use link function in SEM like logit function and probit function i dont find these types of link function in sas but in other program available how can i solve this problem??
02-28-2014 01:13 PM
Transform the data prior to analysis. Unfortunately, if you are doing the multivariate distribution with a cumulative logit, that can get rather difficult. However, there are factor analysis parts to CALIS that I know nothing about, but which might accept categorical data.