galamm (version 0.2.3)

factor_loadings.galamm: Extract factor loadings from galamm object

Description

Extract factor loadings from galamm object

Usage

# S3 method for galamm
factor_loadings(object)

Value

A matrix containing the estimated factor loadings with corresponding standard deviations.

Arguments

object

Object of class galamm returned from galamm.

Author

The example for this function comes from PLmixed, with authors Nicholas Rockwood and Minjeong Jeon rockwoodEstimatingComplexMeasurement2019galamm.

Details

This function has been named factor_loadings rather than just loadings to avoid conflict with stats::loadings.

See Also

fixef.galamm() for fixed regression coefficients, confint.galamm() for confidence intervals, and coef.galamm() for coefficients more generally.

Other details of model fit: VarCorr(), coef.galamm(), confint.galamm(), deviance.galamm(), family.galamm(), fitted.galamm(), fixef(), formula.galamm(), llikAIC(), logLik.galamm(), nobs.galamm(), predict.galamm(), print.VarCorr.galamm(), ranef.galamm(), residuals.galamm(), response(), sigma.galamm(), vcov.galamm()

Examples

# Logistic mixed model with factor loadings, example from PLmixed
data("IRTsim", package = "PLmixed")

# Reduce data size for the example to run faster
IRTsub <- IRTsim[IRTsim$item < 4, ]
IRTsub <- IRTsub[sample(nrow(IRTsub), 300), ]
IRTsub$item <- factor(IRTsub$item)

# Fix loading for first item to 1, and estimate the two others freely
loading_matrix <- matrix(c(1, NA, NA), ncol = 1)

# Estimate model
mod <- galamm(y ~ item + (0 + ability | sid) + (0 + ability | school),
  data = IRTsub, family = binomial, load.var = "item",
  factor = "ability", lambda = loading_matrix
)

# Show estimated factor loadings, with standard errors
factor_loadings(mod)