[R] expressing functions

[Remington, Richard]

# Why does expressing one function

require(ctest)
t.test

# return only

function (x, ...)
UseMethod("t.test")
<environment: namespace:ctest>

# but expressing another function

shapiro.test

# returns more complete code?

function (x)
{
     DNAME <- deparse(substitute(x))
     x <- sort(x[complete.cases(x)])
     n <- length(x)
     if (n < 3 || n > 5000)
         stop("sample size must be between 3 and 5000")
     rng <- x[n] - x[1]
     if (rng == 0)
         stop("all `x[]' are identical")
     if (rng < 1e-10)
         x <- x/rng
     n2 <- n%/%2
     sw <- .C("swilk", init = FALSE, as.single(x), n, n1 = as.integer(n),
         as.integer(n2), a = single(n2), w = double(1), pw = double(1),
         ifault = integer(1), PACKAGE = "ctest")
     if (sw$ifault && sw$ifault != 7)
         stop(paste("ifault=", sw$ifault, ". This should not happen"))
     RVAL <- list(statistic = c(W = sw$w), p.value = sw$pw, method = 
"Shapiro-Wilk normality test",
         data.name = DNAME)
     class(RVAL) <- "htest"
     return(RVAL)
}
<environment: namespace:ctest>

-- 

Richard E. Remington III
Statistician
KERN Statistical Services, Inc.
PO Box 1046
Boise, ID 83701
Tel: 208.426.0113
KernStat.com