\name{expectation-methods} \docType{methods} \alias{expectation} \alias{expectation-methods} \alias{expectation,IndependenceLinearStatistic-method} \alias{expectation,IndependenceTest-method} \alias{variance} \alias{variance-methods} \alias{variance,CovarianceMatrix-method} \alias{variance,IndependenceLinearStatistic-method} \alias{variance,IndependenceTest-method} \alias{variance,Variance-method} \alias{covariance} \alias{covariance-methods} \alias{covariance,CovarianceMatrix-method} \alias{covariance,IndependenceLinearStatistic-method} \alias{covariance,IndependenceTest-method} \title{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{ \S4method{expectation}{IndependenceLinearStatistic}(object, \dots) \S4method{expectation}{IndependenceTest}(object, \dots) \S4method{variance}{CovarianceMatrix}(object, \dots) \S4method{variance}{IndependenceLinearStatistic}(object, \dots) \S4method{variance}{IndependenceTest}(object, \dots) \S4method{variance}{Variance}(object, \dots) \S4method{covariance}{CovarianceMatrix}(object, \dots) \S4method{covariance}{IndependenceLinearStatistic}(object, \dots) \S4method{covariance}{IndependenceTest}(object, \dots) } \arguments{ \item{object}{ an object from which the expectation, variance or covariance of the linear statistic can be extracted. } \item{\dots}{ further arguments (currently ignored). } } \details{ The methods \code{expectation}, \code{variance} and \code{covariance} extract the expectation, variance and covariance, respectively, of the linear statistic. } \value{ The expectation, variance or covariance of the linear statistic extracted from \code{object}. A numeric vector or matrix. } \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") } \keyword{methods}