# coef

##### Extract Model Coefficients

`coef`

is a generic function which extracts model coefficients
from objects returned by modeling functions. `coefficients`

is
an *alias* for it.

- Keywords
- models, regression

##### 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.

##### 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.

##### 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.

##### 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

`library(stats)`

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

*Documentation reproduced from package stats, version 3.5.0, License: Part of R 3.5.0*