# besselh

besselh(nu, k, x)

Bessel function of the third kind of order `nu` (Hankel function). `k` is either 1 or 2, selecting `hankelh1` or `hankelh2`, respectively.

## Examples

1. Compute the Hankel function of the first kind (`hankelh1`):

``````julia> besselh(0.5, 1, 2.0)
0.4482883573538264``````

This example calculates the Hankel function of order 0.5 (`nu`) of the first kind (`hankelh1`) at `x = 2.0`.

2. Compute the Hankel function of the second kind (`hankelh2`):

``````julia> besselh(2, 2, 3.5)
-0.04656529596447402``````

It computes the Hankel function of order 2 (`nu`) of the second kind (`hankelh2`) at `x = 3.5`.

3. Evaluate the Bessel function at multiple points:
``````julia> x = [1.0, 2.0, 3.0, 4.0];
julia> besselh(1, 1, x)
4-element Array{Float64,1}:
0.207115
-0.270151
-0.340043
-0.409775``````

In this example, the `besselh` function is applied to each element in the array `x` and returns an array of the corresponding evaluations.

Common mistake example:

``````julia> besselh(0, 3, 1.5)
ERROR: ArgumentError: Invalid Bessel function type, expected 1 or 2``````

In this example, the value of `k` is provided as `3`, which is invalid. The second argument `k` should be either `1` or `2` to select `hankelh1` or `hankelh2` respectively. Ensure that the value of `k` is correctly specified to avoid such errors.