object.
coef(object, unconstrained) coef(object) <- value
pdMat,
representing a positive-definite matrix.
TRUE the coefficients
are returned in unconstrained form (the same used in the optimization
algorithm). If
FALSE the upper triangular elements of the
positive-definite matrix represented by
object are
returned. Defaults to
TRUE.
object. It must be a vector with the same length
of `coef{object}' and must be given in unconstrained form.
object.
On the left side of an assignment, sets the values of the coefficients
of
object to
value.
Pinheiro, J.C. and Bates., D.M. (1996) "Unconstrained Parametrizations for Variance-Covariance Matrices", Statistics and Computing, 6, 289-296.
coef(pdSymm(diag(3)))