RcmdrPlugin.TeachStat (version 1.1.3)

characRV: Characteristics of Random Variables.

Description

This function computes the main characteristics of a random variable (expectation, median, standard deviation, ...)

Usage

characRV(D, charact = c("expectation", "median", "sd", "IQR", "skewness", "kurtosis", 
         "moment", "cmoment"), moment = 1, cmoment = 2)

Value

`characRV` returns a table containing the selected characteristics.

Arguments

D

An object of the class Distribution.

charact

any of "expectation", "median", "sd", "IQR", "skewness", "kurtosis", "moment", "cmoment"

moment

an integer indicating the moment with respect to the origin to be calculated.

cmoment

an integer indicating the moment with respect to the expectation to be calculated.

See Also

E, median, sd, IQR, skewness, kurtosis

Examples

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (D, charact = c("expectation", "median", "sd", "IQR", 
    "skewness", "kurtosis", "moment", "cmoment"), moment = 1, 
    cmoment = 2) 
{
    if (missing(charact)) 
        charact <- c("expectation", "sd")
    charact <- match.arg(charact, c("expectation", "median", 
        "sd", "IQR", "skewness", "kurtosis", "moment", "cmoment"), 
        several.ok = TRUE)
    moment <- if ("moment" %in% charact) 
        moment
    else NULL
    cmoment <- if ("cmoment" %in% charact) 
        cmoment
    else NULL
    mom <- if (!is.null(moment)) 
        paste("alpha_", moment, sep = "")
    else NULL
    cmom <- if (!is.null(cmoment)) 
        paste("mu_", cmoment, sep = "")
    else NULL
    chars <- c(c("expectation", "median", "sd", "IQR", "skewness", 
        "kurtosis")[c("expectation", "median", "sd", "IQR", "skewness", 
        "kurtosis") %in% charact], mom, cmom)
    nchars <- length(chars)
    table <- matrix(0, 1, nchars)
    rownames(table) <- gsub("[[:space:]]", "", deparse(substitute(D)))
    colnames(table) <- chars
    if ("expectation" %in% chars) 
        table[, "expectation"] <- distrEx::E(D)
    if ("median" %in% chars) 
        table[, "median"] <- distrEx::median(D)
    if ("sd" %in% chars) 
        table[, "sd"] <- distrEx::sd(D)
    if ("IQR" %in% chars) 
        table[, "IQR"] <- distrEx::IQR(D)
    if ("skewness" %in% chars) 
        table[, "skewness"] <- distrEx::skewness(D)
    if ("kurtosis" %in% chars) 
        table[, "kurtosis"] <- distrEx::kurtosis(D)
    if ("moment" %in% charact) 
        table[, mom] <- distrEx::E(D, fun = function(x) {
            x^moment
        })
    if ("cmoment" %in% charact) 
        table[, cmom] <- distrEx::E(D, fun = function(x) {
            (x - distrEx::E(D))^cmoment
        })
    print(table)
    return(invisible(table))
  }