| zeta {sn} | R Documentation |
The function log(2 P(x)) and its derivatives up to order 4,
if P(x) denotes the standard normal distribution function.
zeta(k, x)
k |
an integer scalar. |
x |
a vector. Missing values (NAs) are allowed, but Infs are not.
|
k denotes the order of the derivative. If k is 0, the function
is evaluated, using pnorm(x) for x>-35, an asymptotic expansion
otherwise. For k between 1 and 4, the derivative of that order is
evaluated. For k>4, a warning message is issued, and a vector of
NAs is returned.
This function is used by sn.dev and msn.dev, among others.
a vector; this is the k-th order derivative evaluated at x
y <- zeta(2,seq(-20,20,by=0.5))
for(i in 0:4)
curve(zeta(i,x),-3, 4, ylim = c(-1,2), col = i+1, add = i > 0)