getTheta {BifactorIndicesCalculator}

getTheta

Description

getTheta extracts or computes a vector of residual variance for items. If a factor loading matrix is provided, then the vector of residual variances is computed from that matrix if standardized is TRUE.

Usage

getTheta(x, standardized = TRUE)

Arguments

x

an object that can be converted into a factor loading matrix, or an object containing a fitted model from which a vector of residual variances can be extracted. Supported classes are data.frame, matrix, mplus.model, lavaan, and SingleGroupClass

standardized

can be used to specify whether a standardized or unstandardized factor loading matrix should be returned. Only relevant for lavaan and mplus.model input. The standardized matrix for mplus.model is taken from stdyx results.

Value

a vector of residual variances for items. If x is a fitted model, then the residual variances are extracted from the fitted model. lavaan, mirt (SingleGroupClass), and Mplus (mplus.model) models are supported. If Mplus does not report residual variances for categorical variables, then factor loadings are used to compute the residual variance for standardized models and an error is thrown for unstandardized models. In both cases, the user is alerted that residual variances could not be found in the input and perhaps the model should be rerun.

See Also

getLambda