Description Usage Arguments Details Value Methods Author(s) See Also Examples
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 S4 generic function takes a numeric vector of free parameters and
manipulates it into the matrices that are typical when estimating a
factor analysis model. There is little need to call it directly. Various
methods are defined for the restrictions
object, corresponding to
different kinds of factor analysis models; see FAiR-package
.
1 2 | ## S4 method for signature 'restrictions,manifest'
restrictions2model(par, restrictions, manifest, lower, mapping_rule)
|
par |
A numeric vector containing values for all the free parameters
to be estimated, which corresponds to the |
restrictions |
An object of |
manifest |
An object of |
lower |
A small numeric scalar indicating the lower bound for positive
definiteness or minimum uniqueness; see the corresponding argument
to |
mapping\_rule |
a logical that controls whether the mapping rule is invoked in
semi-exploratory factor analysis. This argument is used to circumvent
the mapping rule in some circumstances, like when the function is called
indirectly by |
This function is called internally by Factanal
thousands of times
during the course of the optimization. Let the factor analysis model in the population be
Sigma = Omega(beta Phi beta' + Theta)Omega
and let theta be a vector of all the free parameters in the factor
analysis model. The restrictions2model
methods are essentially a mapping
from theta to the free elements of beta,
Phi, and Omega. The methods are currently defined on
the restrictions
argument, which is fairly skeletal at the outset, is
filled in by the body of the restrictions2model
method using a bunch of
calls to the make_parameter-methods
.
The restrictions2model
method can (and does) also do some checking of
whether the parameters in par
are admissable in the context of a factor
analysis model. For each admissability check, if par
is admissable, it
should receive the value of -1.0 in a numeric vector whose length is equal
to the number of admissability checks. If par
is inadmissable with respect
to some check, it should receive a value greater than -1.0. This numeric
vector should also be returned as an element of a list called "criteria"
.
A list with exactly two elements named
criteria |
a numeric vector |
restrictions |
a filled-in version of the |
The arguments that are part of the signature are restrictions
and
manifest
. Methods are currently only defined for objects of class
"manifest.basic"
, which are inherited by objects of class
"manifest.data"
and "manifest.data.mcd"
. There are methods
for each of the classes that inherit from restrictions-class
,
except for "restrictions.factanal"
, which does not utilize the
restrictions2model
mechanism.
There are also two arguments that are not part of the signature.
The first is par
, which is a numeric vector of free parameters and
is conceptually similar to the par
argument to optim
.
The second is lower
, which is a small positive number that is used
as a threshold for positive-definiteness of various matrices.
Ben Goodrich
make_parameter
, restrictions-class
1 | showMethods("restrictions2model")
|
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