stats (version 3.5.2)

coef: Extract Model Coefficients

Description

coef is a generic function which extracts model coefficients from objects returned by modeling functions. coefficients is an alias for it.

Usage

coef(object, …)
coefficients(object, …)
# S3 method for default
coef(object, complete = TRUE, …)
# S3 method for aov
coef(object, complete = FALSE, …)

Arguments

object

an object for which the extraction of model coefficients is meaningful.

complete

for the default (used for lm, etc) and aov methods: logical indicating if the full coefficient vector should be returned also in case of an over-determined system where some coefficients will be set to NA, see also alias. Note that the default differs for lm() and aov() results.

…

other arguments.

Value

Coefficients extracted from the model object object.

For standard model fitting classes this will be a named numeric vector. For "maov" objects (produced by aov) it will be a matrix.

Details

All object classes which are returned by model fitting functions should provide a coef method or use the default one. (Note that the method is for coef and not coefficients.)

The "aov" method does not report aliased coefficients (see alias) by default where complete = FALSE.

The complete argument also exists for compatibility with vcov methods, and coef and aov methods for other classes should typically also keep the complete = * behavior in sync. By that, with p <- length(coef(obj, complete = TF)), dim(vcov(obj, complete = TF)) == c(p,p) will be fulfilled for both complete settings and the default.

References

Chambers, J. M. and Hastie, T. J. (1992) Statistical Models in S. Wadsworth & Brooks/Cole.

See Also

fitted.values and residuals for related methods; glm, lm for model fitting.

Examples

# NOT RUN {
x <- 1:5; coef(lm(c(1:3, 7, 6) ~ x))
# }