Function argmin_testfunctions::holder_table_hessian

pub fn holder_table_hessian<T>(param: &[T; 2]) -> [[T; 2]; 2]
where
    T: Float + FromPrimitive,

Hessian of the Holder table test function

This function has a discontinuity at sqrt(x_1^2+x_2^2) = PI, and hence can return NaN.