.\" -*- nroff -*- generated from .Rd format
.BG
.FN pdMat
.TL
Positive-Definite Matrix
.DN
This function gives an alternative way of constructing an object
inheriting from the `pdMat' class named in `pdClass', or
from `data.class(object)' if `object' inherits from
`pdMat',  and is mostly used internally in other functions. See
the documentation on the principal constructor function, generally
with the same name as the `pdMat' class of object.
.CS
pdMat(value, form, nam, data, pdClass)
.OA
.AG value
an optional initialization value, which can be any of the
following: a `pdMat' object, a positive-definite
matrix, a one-sided linear formula (with variables separated by
`+'), a vector of character strings, or a numeric
vector. Defaults to `numeric(0)', corresponding to an
uninitialized object.
.AG form
an optional one-sided linear formula specifying the
row/column names for the matrix represented by `object'. Because
factors may be present in `form', the formula needs to be
evaluated on a data.frame to resolve the names it defines. This
argument is ignored when `value' is a one-sided
formula. Defaults to `NULL'.
.AG nam
an optional vector of character strings specifying the
row/column names for the matrix represented by object. It must have 
length equal to the dimension of the underlying positive-definite
matrix and unreplicated elements. This argument is ignored when
`value' is a vector of character strings. Defaults to
`NULL'.
.AG data
an optional data frame in which to evaluate the variables named in
`value' and `form'. It is used to obtain the levels for `factors',
which affect the dimensions and the row/column names of the underlying
matrix. If `NULL', no attempt is made to obtain information on
`factors' appearing in the formulas. Defaults to the
parent frame from which the function was called.
.AG pdClass
an optional character string naming the
`pdMat' class to be assigned to the returned object. This
argument will only be used when `value' is not a `pdMat' 
object. Defaults to `"pdSymm"'.
.RT
a `pdMat' object representing a positive-definite matrix,
inheriting from the class named in `pdClass', or from
`class(object)', if `object' inherits from `pdMat'.

.SA
`pdCompSymm', `pdDiag',
`pdIdent', `pdSymm'
.EX
pd1 <- pdMat(diag(1:4), pdClass = "pdDiag")
pd1
.KW models
.WR
