coin (version 1.1-2)

expectation-methods: Extraction of the Expectation, Variance and Covariance of the Linear Statistic

Description

Methods for extraction of the expectation, variance and covariance of the linear statistic.

Usage

"expectation"(object, ...)
"expectation"(object, ...)
"variance"(object, ...)
"variance"(object, ...)
"variance"(object, ...)
"variance"(object, ...)
"covariance"(object, ...)
"covariance"(object, ...)
"covariance"(object, ...)

Arguments

object

an object from which the expectation, variance or covariance of the linear statistic can be extracted.

...

further arguments (currently ignored).

Value

The expectation, variance or covariance of the linear statistic extracted from object. A numeric vector or matrix.

Details

The methods expectation, variance and covariance extract the expectation, variance and covariance, respectively, of the linear statistic.

Examples

## Example data
dta <- data.frame(
    y = gl(3, 2),
    x = sample(gl(3, 2))
)

## Asymptotic Cochran-Mantel-Haenszel Test
ct <- cmh_test(y ~ x, data = dta)

## The linear statistic, i.e., the contingency table...
(l <- statistic(ct, type = "linear"))

## ...and its expectation...
(El <- expectation(ct))

## ...and covariance
(Vl <- covariance(ct))

## The standardized contingency table...
(l - El) / sqrt(variance(ct))

## ...is identical to the standardized linear statistic
statistic(ct, type = "standardized")