ellipse:

In musto101/wilcox_R: What the package does (short line)

Usage

ellipse(x, center = apply(x, 2, mean), cov = var(x), alph = 0.95)

Arguments

x
center
cov
alph

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 (x, center = apply(x, 2, mean), cov = var(x), alph = 0.95) 
{
    mu1 <- center[1]
    mu2 <- center[2]
    w <- solve(cov)
    w11 <- w[1, 1]
    w12 <- w[1, 2]
    w22 <- w[2, 2]
    tem <- x[, 2] - mu2
    y2 <- seq(min(tem), max(tem), length = 100)
    xc <- qchisq(alph, 2)
    el <- matrix(0, 2, 2)
    ind <- 0
    for (i in 1:100) {
        j1 <- (y2[i] * w12)^2
        j2 <- w11 * ((y2[i])^2 * w22 - xc)
        if ((j1 - j2) >= 0) {
            ind <- ind + 2
            tem <- (y2[i] * w12)^2
            tem <- tem - w11 * ((y2[i])^2 * w22 - xc)
            tem <- sqrt(tem)
            term <- (-y2[i] * w12 + tem)/w11
            el <- rbind(el, c((term + mu1), (y2[i] + mu2)))
            term <- (-y2[i] * w12 - tem)/w11
            el <- rbind(el, c((term + mu1), (y2[i] + mu2)))
        }
    }
    el <- el[3:ind, ]
    nn <- dim(x)[1]
    if ((ind - 2) > nn) {
        tem <- sample((ind - 2), nn)
        el <- el[tem, ]
    }
    xt <- cbind(x[, 1], el[, 1])
    yt <- cbind(x[, 2], el[, 2])
    matplot(xt, yt)
  }

musto101/wilcox_R documentation built on May 23, 2019, 10:52 a.m.