pdMat-class {Matrix}R Documentation

Class pdMat, positive-definite matrices

Description

A virtual class of parameterized positive-definite symmetric matrices. This class describes the slots and methods that actual classes of positive-definite matrices are expected to incorporate. Some classes that inherit from pdMat have additional slots and methods.

Objects from the Class

Objects of class pdMat are not constructed directly; only objects from classes that inherit from pdMat are constructed.

Slots

form:
Object of class "formula", holds the formula for the object
Names:
Object of class "character" holding the names of the rows (and columns) of the positive-definite symmetric matrix represented by the object.
param:
"numeric" - the parameter vector.
Ncol:
"integer" - the number of columns (and rows) in the matrix.
factor:
"matrix" - a square-root factor of the matrix.
logDet:
"numeric" - the logarithm of the determinant of the factor.

Methods

coerce
signature(from = "pdMat", to = "pdfactor"): extract a square-root factor of the matrix represented by the object. This factor has a logDet slot giving the logarithm of its determinant. In the case of pdLogChol these are both scalars and the logDet attribute is the logarithm of the absolute value of the factor.
corMatrix
signature(object = "pdMat"): Extract the correlation matrix corresponding to the positive-definite matrix represented by the object. This method is present for back compatibility only. The preferred way of extracting the correlation matrix is to coerce the object to the "corrmatrix" class.
dim
signature(x = "pdMat"): the dimensions of the positive-definite matrix represented by the object.
formula
signature(x = "pdMat"): extract the formula
isInitialized
signature(object = "pdMat"): TRUE if the object has been initialized, otherwise FALSE.
logDet
signature(object = "pdMat", covariate = "missing"): the logarithm of the determinant of the factor of the positive-definite matrix represented by the object.
names
signature(x = "pdMat"): extract a vector of names, which are both the column names and the row names of the positive-definite matrix represented by the object.
names<-
signature(x = "pdMat"): assign the names,
pdFactor
signature(object = "pdMat"): Extract the square root factor of positive-definite symmetric matrix represented by the object. This method is present for back compatibility only. The preferred way of extracting the factor is to coerce the object to the "pdfactor" class.
pdMatrix
signature(object = "pdMat"): Extract the positive-definite symmetric matrix represented by the object. This method is present for back compatibility only. The preferred way of extracting the positive-definite symmetric matrix is to coerce the object to the "pdmatrix" class.
show
signature(x = "pdMat"): show the object.
solve
signature(a = "pdMat", b = "missing"): Create an object of the same class representing the inverse of the positive-definite matrix.
summary
signature(object = "pdMat"):

Note

pdMat objects are primarily used to represent the variance-covariance matrix or the precision matrix of random-effects terms in mixed-effects models. Frequently they are constructed from a formula only in the call to the mixed-effects modelling function then assigned a value as part of the initialization of the model.

References

See Also

pdCompSymm-class, pdDiag-class, pdLogChol-class, pdIdent-class


[Package Contents]