nlme (version 3.1-99)

pdConstruct: Construct pdMat Objects

Description

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, ...)

Arguments

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

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

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 ignor

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.

...

optional arguments for some methods.

Value

• a pdMat object representing a positive-definite matrix, inheriting from the same classes as object.

See Also

pdCompSymm, pdDiag, pdIdent, pdNatural, pdSymm

Examples

pd1 <- pdSymm()
pdConstruct(pd1, diag(1:4))