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.
USAGE:
pdConstruct(object, value, form, nam, data)
REQUIRED ARGUMENTS:
object
an object inheriting from class
pdMat, representing
a positive definite matrix.
OPTIONAL ARGUMENTS:
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.
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.
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.
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.
VALUE:
a
pdMat object representing a positive-definite matrix,
inheriting from the same classes as
object.