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 (NA s) and Inf s 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)