.\" -*- nroff -*- generated from .Rd format
.BG
.FN pdConstruct
.TL
Construct pdMat Objects
.DN
This function is an alternative constructor for the `pdMat'
class associated with `object' 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
pdConstruct(object, value, form, nam, data)
.RA
.AG object
an object inheriting from class `pdMat', representing
a positive definite matrix.
.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.
.RT
a `pdMat' object representing a positive-definite matrix,
inheriting from the same classes as `object'.

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