TANG Xiaoyu, postgraduate, majors in geodesy and surveying engineering, E-mail: 6720230182@mail.jxust.edu.cn
We derive five spherical harmonic analysis algorithms in detail and develop a user-friendly and easy-to-operate practical software using the scientific computing language MATLAB. To validate the performance of five algorithms, we conduct a numerical analysis of the computational efficiency and accuracy of fast Fourier transform(FFT), least squares(LS), weighted least squares(WLS), approximate quadrature(AQ), and first Neumann method(FNM) algorithms at harmonic degrees of 180, 360, 720, 1 800 and 2 160, using the global topographic data DTM2006.0 as a case study. The results show that the AQ algorithm performs best in terms of computational efficiency, while the LS algorithm achieves the highest precision. The residuals of all five algorithms approximately follow a normal distribution, indicating that none of five algorithms exhibit systematic biases.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |