pdIdent: Multiple of the Identity Positive-Definite Matrix
Description
This function is a constructor for the pdIdent class,
representing a multiple of the identity positive-definite matrix.
The matrix associated with object is represented by 1
unrestricted parameter, given by the logarithm of the square-root of
the diagonal value. When value is
numeric(0), an uninitialized pdMat object, a one-sided
formula, or a vector of character strings, object is returned
as an uninitialized pdIdent object (with just some of its
attributes and its class defined) and needs to have its coefficients
assigned later, generally using the coef or matrix replacement
functions. If value is an initialized pdMat object,
object will be constructed from
as.matrix(value). Finally, if value is a numeric value,
it is assumed to represent the unrestricted coefficient of the
underlying positive-definite matrix.
Usage
pdIdent(value, form, nam, data)
Arguments
Value
a pdIdent object representing a multiple of the identity
positive-definite matrix, also inheriting from class pdMat.
References
Pinheiro, J.C., and Bates, D.M. (2000) "Mixed-Effects Models
in S and S-PLUS", Springer.