Function argmin_testfunctions::sphere_derivative_const

pub fn sphere_derivative_const<const N: usize, T>(param: &[T; N]) -> [T; N]
where
    T: Float + FromPrimitive,

Derivative of sphere test function

Defined as

f(x_1, x_2, ..., x_n) = (2 * x_1, 2 * x_2, ... 2 * x_n)

where x_i \in (-\infty, \infty) and n > 0.

This is the const generics version, which requires the number of parameters to be known at compile time.