import numpy as np
from scipy import linalg

from leap_ec.real_rep.problems import plot_2d_function

def sinc_hd(phenome):
    r = linalg.norm(phenome)
    return np.sin(r)/r

plot_2d_function(sinc_hd, xlim=(-10, 10), ylim=(-10, 10), granularity=0.2)