# statistic-methods

##### Extraction of the Test Statistic and Linear Statistic

Methods for extraction of the test statistic and linear statistic.

- Keywords
- methods

##### Usage

```
# S4 method for IndependenceLinearStatistic
statistic(object, type = c("test", "linear", "centered", "standardized"), …)
# S4 method for IndependenceTestStatistic
statistic(object, type = c("test", "linear", "centered", "standardized"), …)
# S4 method for IndependenceTest
statistic(object, type = c("test", "linear", "centered", "standardized"), …)
```

##### Arguments

- object
an object from which the test statistic or linear statistic can be extracted.

- type
a character, the type of statistic: either

`"test"`

(default) for the test statistic,`"linear"`

for the unstandardized linear statistic`"centered"`

for the centered linear statistic or`"standardized"`

for the standardized linear statistic.- …
further arguments (currently ignored).

##### Details

The method `statistic`

extracts the test statistic or the, possibly
multivariate, linear statistic in its unstandardized, centered or
standardized form.

The test statistic (`type = "test"`

) is returned by default. The
unstandardized, centered or standardized linear statistic is obtained by
setting `type`

to `"linear"`

, `"centered"`

or
`"standardized"`

respectively.

##### Value

The test statistic or the unstandardized, centered or standardized linear
statistic extracted from `object`

. A numeric vector or matrix.

##### Examples

```
# NOT RUN {
## Example data
dta <- data.frame(
y = gl(4, 5),
x = gl(5, 4)
)
## Asymptotic Cochran-Mantel-Haenszel Test
ct <- cmh_test(y ~ x, data = dta)
## Test statistic
statistic(ct)
## The unstandardized linear statistic...
statistic(ct, type = "linear")
## ...is identical to the contingency table
xtabs(~ x + y, data = dta)
## The centered linear statistic...
statistic(ct, type = "centered")
## ...is identical to
statistic(ct, type = "linear") - expectation(ct)
## The standardized linear statistic, illustrating departures from the null
## hypothesis of independence...
statistic(ct, type = "standardized")
## ...is identical to
(statistic(ct, type = "linear") - expectation(ct)) / sqrt(variance(ct))
# }
```

*Documentation reproduced from package coin, version 1.3-1, License: GPL-2*