# summary

##### Object Summaries

`summary`

is a generic function used to produce result summaries
of the results of various model fitting functions. The function
invokes particular `methods`

which depend on the
`class`

of the first argument.

- Keywords
- methods

##### Usage

`summary(object, …)`# S3 method for default
summary(object, …, digits)
# S3 method for data.frame
summary(object, maxsum = 7,
digits = max(3, getOption("digits")-3), …)

# S3 method for factor
summary(object, maxsum = 100, …)

# S3 method for matrix
summary(object, …)

# S3 method for summaryDefault
format(x, digits = max(3L, getOption("digits") - 3L), …)
# S3 method for summaryDefault
print(x, digits = max(3L, getOption("digits") - 3L), …)

##### Arguments

- object
an object for which a summary is desired.

- x
a result of the

*default*method of`summary()`

.- maxsum
integer, indicating how many levels should be shown for

`factor`

s.- digits
integer, used for number formatting with

`signif()`

(for`summary.default`

) or`format()`

(for`summary.data.frame`

). In`summary.default`

, if not specified (i.e.,`missing(.)`

),`signif()`

will*not*be called anymore (since R >= 3.4.0, where the default has been changed to only round in the`print`

and`format`

methods).- …
additional arguments affecting the summary produced.

##### Details

For `factor`

s, the frequency of the first `maxsum - 1`

most frequent levels is shown, and the less frequent levels are
summarized in `"(Others)"`

(resulting in at most `maxsum`

frequencies).

The functions `summary.lm`

and `summary.glm`

are examples
of particular methods which summarize the results produced by
`lm`

and `glm`

.

##### Value

The form of the value returned by `summary`

depends on the
class of its argument. See the documentation of the particular
methods for details of what is produced by that method.

The default method returns an object of class
`c("summaryDefault", "table")`

which has specialized
`format`

and `print`

methods. The
`factor`

method returns an integer vector.

The matrix and data frame methods return a matrix of class
`"table"`

, obtained by applying `summary`

to each
column and collating the results.

##### References

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

##### See Also

##### Examples

`library(base)`

```
summary(attenu, digits = 4) #-> summary.data.frame(...), default precision
summary(attenu $ station, maxsum = 20) #-> summary.factor(...)
lst <- unclass(attenu$station) > 20 # logical with NAs
## summary.default() for logicals -- different from *.factor:
summary(lst)
summary(as.factor(lst))
```

*Documentation reproduced from package base, version 3.4.1, License: Part of R 3.4.1*