coef.ltm {ltm}R Documentation

Loadings for ltm objects

Description

Extracts the estimated parameters from an ltm object.

Usage

coef.ltm(object, standardized = FALSE, ...)

Arguments

object an object inheriting from class ltm.
standardized logical; if TRUE the standardized loadings are also returned. See Details for more info.
... additional arguments; currently none is used.

Details

The standardization of the factor loadings is useful in order to form a link to the Underlying Variable approach. In particular, the standardized form of the factor loadings represents the correlation coefficient between the latent variables and the underlying continuous variables based on which the dichotomous outcomes arise (see Bartholomew and Knott, 1999, p.87-88 or Bartholomew et al., 2002, p.191).

The standardized factor loadings are computed only for the linear one- and two-factor models.

Value

The matrix of the estimated parameters for the fitted model.

References

Bartholomew, D. and Knott, M. (1999) Latent Variable Models and Factor Analysis, 2nd ed. London: Arnold.

Bartholomew, D., Steel, F., Moustaki, I. and Galbraith, J. (2002) The Analysis and Interpretation of Multivariate Data for Social Scientists. London: Chapman and Hall.

See Also

ltm

Examples


m1 <- ltm(Lsat~z1)
coef(m1)
coef(m1, TRUE)

m2 <- ltm(Wirs~z1+z2)
coef(m2)
coef(m2, TRUE)


[Package ltm version 0.1-1 Index]