FAiR (version 0.2-0)

restrictions-class: Class "restrictions"

Description

It is not necessary to understand this help page if one merely wants to estimate a factor analysis model. This help page is intended for those who want to modify or extend FAiR or otherwise want some idea of how FAiR works ``behind the scenes''. This class contains information in its slots about what restrictions are placed on a factor analysis model. As an overview, objects of class "restrictions.factanal" are handled by methods that are analagous to the algorithm in factanal. Objects of class "restrictions.orthonormal" are handled by methods that estimate an exploratory factor analysis model with orthogonal factors and zeros in the upper triangle of the coefficient matrix. Objects of class "restrictions.1storder", "restrictions.general", and "restrictions.2ndorder" are handled by methods that respecitvely estimate semi-exploratory or confirmatory models for a single equation model with correlated factors, a model with a general second-order factor and a model with multiple correlated second-order factors.

Objects from the Class

Objects can be created by calls of the form new("restrictions", ...). However, it is not recommended to do so in normal usage. make_restrictions provides a constructor that reacts to the responses the user gives to the pop-up menus, but it too would rarely need to be called explicitly since it is called internally by Factanal when the restrictions argument to Factanal is unspecified. There are several examples of manual creation of objects of class "restrictions" in the tests.R file in the FAiR/tests subdirectory and in the examples for Factanal.Rd in the FAiR/man subdirectory.

Details

Essentially, an object that inherits from class "restrictions" acts as a vessel that contains matrices and necessary information to estimate the corresponding model. The par argument to the methods for fitS4-methods, bfgs_fitS4-methods, and gr_fitS4-methods fills the free elements of the appropriate matrix and then the appropriate functions are evaluated in search of the optimal parameters that satisfy the constraints. For more details, see the Classes.R and S4methods.R files in the FAiR/R subdirectory.

See Also

Factanal and S4GenericsFAiR

Examples

showClass("restrictions")
showClass("restrictions.orthonormal")
showClass("restrictions.1storder")
showClass("restrictions.general")
showClass("restrictions.2ndorder")