pdIdent
class,
representing a multiple of the identity positive-definite matrix.
The matrix associated with object
is represented by 1
unrestricted parameter, given by the logarithm of the square-root of
the diagonal value. When value
is
numeric(0)
, an uninitialized pdMat
object, a one-sided
formula, or a vector of character strings, object
is returned
as an uninitialized pdIdent
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
replacement
functions. If value
is an initialized pdMat
object,
object
will be constructed from
as.matrix(value)
. Finally, if value
is a numeric value,
it is assumed to represent the unrestricted coefficient of the
underlying positive-definite matrix.pdIdent(value, form, nam, data)
pdMat
object, a positive-definite
matrix, a one-sided linear formula (with variables separated by
+
), a vector of character strings, or a numeric
value. Defaults to numeric(0)
, corresponding
to an uninitialized object.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
.value
is a vector of character strings. Defaults to
NULL
.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.pdIdent
object representing a multiple of the identity
positive-definite matrix, also inheriting from class pdMat
.as.matrix.pdMat
,
coef.pdMat
,
pdClasses
,
matrix<-.pdMat
pd1 <- pdIdent(4 * diag(3), nam = c("A","B","C"))
pd1
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