General structural equation model builder

Assembles a complete SEM from a measurement specification and an optional structural specification, the flexible route when no single-purpose motif fits. Factors named in measurement become latent continuous vertices; their indicators become observed continuous vertices with the first loading fixed to one for scaling (unless scaling = "variance"). Structural regressions and covariances are added as dep and cov edges respectively.

Usage

umg_sem(
  measurement,
  structural = list(),
  covariances = list(),
  scaling = c("marker", "variance"),
  observed = character(0),
  badge = c("statistical", "structural"),
  plate_index = "i = 1, ..., N"
)

Arguments

measurement: Named list mapping each latent factor name to a character vector of its indicator names.
structural: Optional list of length-2 character vectors c(from, to) giving directed regressions among factors and/or observed variables.
covariances: Optional list of length-2 character vectors giving symmetric covariance edges.
scaling: "marker" (fix first loading to 1, the default) or "variance" (fix the factor variance to 1; no marker loading). Under variance scaling, exogenous factors are annotated N(0, 1) and endogenous factors carry a fixed unit residual variance (resid var = 1), matching the convention of lavaan's std.lv = TRUE, so every factor's scale is fixed.
observed: Optional character vector of additional observed variables referenced only in structural/covariances.
badge: "statistical" (default) or "structural".
plate_index: Index label for the person plate.

Value

An object of class umg.

Examples

m <- umg_sem(
  measurement = list(F1 = c("y1", "y2", "y3"),
                     F2 = c("y4", "y5", "y6")),
  structural  = list(c("F1", "F2"))
)
plot(m)