| zeta {sn} | R Documentation |
The function log(2*(pnorm(x)) and its derivatives up to order 4.
zeta(k, x)
k |
an integer scalar between 0 and 4. |
x |
a vector. Missing values (NAs) and Infs are allowed
|
For k between 0 and 4, the derivative of order k
of log(2*pnorm(x)) is evaluated, where the derivative of
order k=0 refers to the function itself.
If k is not integer, it is converted to integer and a warning
message is generated.
If k<0 or k>4, NULL is returned.
This function is used by sn.dev and msn.dev, among others.
a vector giving the k-th order derivative evaluated at x
y <- zeta(2,seq(-20,20,by=0.5)) # for(k in 0:4) curve(zeta(k,x), from=-1, to=5, col = k+2, add = k > 0) legend(3, -0.5, legend=as.character(0:4), col=2:6, lty=1)