| pdConstruct {nlme} | R Documentation |
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.
pdConstruct(object, value, form, nam, data, ...)
object |
an object inheriting from class pdMat, representing
a positive definite matrix. |
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. |
... |
optional arguments for some methods. |
a pdMat object representing a positive-definite matrix,
inheriting from the same classes as object.
Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu
pdCompSymm, pdDiag,
pdIdent, pdNatural, pdSymm
pd1 <- pdSymm() pdConstruct(pd1, diag(1:4))