三维曲面拟合，用于matlab计算

A=[11.105	7.9631	8.905
15.625	5.6948	6.875
16.625	7.8674	6.55
31.155	8.1429	6.74
43.63	11.8269	2.13
40.905	7.0888	6.65
58.61	12.5497	2.35
11.495	6.7651	8.705
22.755	5.9658	10.725
24.39	8.869	8.105
30.865	30.7721	5.18
68.94	16.21	2.94
37.99	8.93	9.34
69.085	15.888	2.725
37.935	12.053	6.715
47.895	12.2803	5.975
24.835	12.677	7.255
39.815	12.5599	6.61
34.15	10.7713	7.03
50.415	12.1127	5.76
33.78	11.2617	7.155
39.325	12.3186	6.765
34.735	12.0524	6.7
28.895	8.5408	6.23
48.615	13.2688	5.25
17.775	9.7091	6.57
41.31	14.393	5.84
19.69	8.814	6.685
52.