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))
# }