nlme (version 3.1-31)

corSymm: General Correlation Structure

Description

This function is a constructor for the corSymm class, representing a general correlation structure. The internal representation of this structure, in terms of unconstrained parameters, uses the spherical parametrization defined in Pinheiro and Bates (1996). Objects created using this constructor must later be initialized using the appropriate Initialize method.

Usage

corSymm(value, form, fixed)

Value

an object of class corSymm representing a general correlation structure.

References

Pinheiro, J.C. and Bates., D.M. (1996) "Unconstrained Parametrizations for Variance-Covariance Matrices", Statistics and Computing, 6, 289-296.

See Also

Initialize.corSymm

Examples

## covariate is observation order and grouping factor is Subject
cs1 <- corSymm(form = ~ 1 | Subject)