Table 1. Coefficients of the shell decomposition (8) of the function G(x) obtained for |x| ≤ 10, M = 21 [see Fig. 3 ▸(b)].

The central peak of G(x) is represented by the sum of the Gaussian function and the correcting function . Each Fourier ripple is represented by one term alternating the sign of κ _m . The maximal error of the approximation is about 2 × 10⁻⁴ of the maximum of G(x) equal to 1

M	μ	ν	κ	M	μ	ν	κ	M	μ	ν	κ
1	0.000	10.131	0.693	8	3.492	2.795	0.485	15	6.989	1.670	−0.368
2	0.339	3.216	0.026	9	3.971	2.882	−0.476	16	7.490	1.509	0.356
3	0.873	4.819	−0.797	10	4.471	2.022	0.401	17	7.991	1.369	−0.334
4	1.439	3.622	0.595	11	4.995	1.620	−0.371	18	8.493	1.248	0.326
5	1.979	3.616	−0.599	12	5.504	2.317	0.416	19	8.995	1.146	−0.332
6	2.462	4.143	0.623	13	5.980	2.062	−0.407	20	9.494	1.060	0.333
7	2.953	3.047	−0.534	14	6.490	1.849	0.392	21	9.978	0.811	−0.290