Function rbf_polynomial

tests/testutils.py:248–252

(r, n, l)

    betas = sqrtm(np.linalg.inv(S))

    def rbf_polynomial(r, n, l):
        poly = 0
        for k in range(1, n_max + 1):
            poly += betas[n, k - 1] * (r_cut - np.clip(r, 0, r_cut)) ** (k + 2)
        return poly

    return soap_integration(system, centers, args, rbf_polynomial)