nlme (version 3.1-99)

formula.pdMat: Extract pdMat Formula

Description

This method function extracts the formula associated with a pdMat object, in which the column and row names are specified.

Usage

## S3 method for class 'pdMat':
formula(x, asList, \dots)

Arguments

x

an object inheriting from class pdMat, representing a positive definite matrix.

asList

logical. Should the asList argument be applied to each of the components? Never used.

...

some methods for this generic require additional arguments. None are used in this method.

Value

• if x has a formula attribute, its value is returned, else NULL is returned.

See Also

pdMat

Examples

pd1 <- pdSymm(~Sex*age)
formula(pd1)