lme4 (version 0.3-1)

pdLogChol-class: Class "pdLogChol", positive-definite matrices

Description

A class of general, positive-definite symmetric matrices parameterized by the non-zero elements in the Cholesky decomposition. The diagonal elements are represented by their logarithms in the first q positions of the parameter vector. The strict upper triangle of the factor is in the last q(q-1)/2 positions.

Arguments

Objects from the Class

Objects of class pdLogChol can be created by calls of the form new("pdLogChol", ...) or by the generic constructor function pdLogChol. Frequently the constructor is given a formula only, creating an uninitialized pdLogChol object which is later assigned a value.

pdLogChol objects are primarily used to represent the variance-covariance matrix or the precision matrix of random-effects terms in mixed-effects models.

Extends

Class "pdMat", directly.

See Also

pdMat-class

Examples

Run this code
m1 <- pdLogChol(~ age)
coef(m1) <- rnorm(3)
print(m1)
solve(m1)

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