This function is a constructor for the
pdBlocked class,
representing a positive-definite block-diagonal matrix. Each
block-diagonal element of the underlying matrix is itself a
positive-definite matrix and is represented internally as an
individual
pdMat object. When
value is
numeric(0)
, a list of uninitialized
pdMat objects, a
list of one-sided formulas, or a list of vectors
of character strings,
object is returned
as an uninitialized
pdBlocked 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}
functions. If
value is a list of initialized
pdMat
objects,
object will be constructed from the list obtained by
applying
as.matrix to each of the
pdMat elements of
value
. Finally, if
value is a list of numeric vectors,
they are assumed to represent the unrestricted coefficients
of the block-diagonal elements of the underlying positive-definite
matrix.
USAGE:
pdBlocked(value, form, nam, data, pdClass)
OPTIONAL ARGUMENTS:
value
an optional list with elements to be used as the
value argument to other
pdMat constructors. These
include:
pdMat objects, positive-definite
matrices, one-sided linear formulas, vectors of character strings, or
numeric vectors. All elements in the list must be similar (e.g. all
one-sided formulas, or all numeric vectors). Defaults to
numeric(0), corresponding to an uninitialized object.
form
an optional list of one-sided linear formulas specifying the
row/column names for the block-diagonal elements of the matrix
represented by
object. Because factors may be present in
form, the formulas needs to be evaluated on a data.frame to
resolve the names they define. This argument is ignored when
value is a list of one-sided formulas. Defaults to
NULL.
nam
an optional list of vector of character strings specifying the
row/column names for the block-diagonal elements of the matrix
represented by object. Each of its components must have
length equal to the dimension of the corresponding block-diagonal
element and unreplicated elements. This argument is ignored when
value is a list of 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 any
factors appearing in the formulas. Defaults to the parent
frame from which the function was called.
pdClass
an optional vector of character strings naming the
pdMat classes to be assigned to the individual blocks in the
underlying matrix. If a single class is specified, it is used for all
block-diagonal elements. This argument will only be used when
value is missing, or its elements are not
pdMat
objects. Defaults to
"pdSymm".
VALUE:
a
pdBlocked object representing a positive-definite
block-diagonal matrix, also inheriting from class
pdMat.