I am trying to reparameterize a multivariate piecewise growth model (with 3 alcohol use measures) into a higher-order factor of curves model, but I continue to get an error message ...NOT POSITIVE DEFINITE." because one of my first-order latent variables has a negative residual variance, but I am not sure how to fix this.
Thanks. Please find my syntax in a subsequent post
Model ib s1b | ...; ib s2b | ...; if s1f | ...; if s2f | ...; iq s1q | ...; iq s2q | ...; itot by if* (1); itot by iq* (2); s1tot by s1f* (1); s1tot by s1q* (2); s2tot by s2f* (1); s2tot by s2q* (2); itot by ib@1; s1tot by s1b@1; s2tot by s2b@1;