当我每次加载的时候：
from geoist.magmod.magnetic_model.loader_igrf import load_model_igrf
from geoist.magmod.magnetic_model.loader_wmm import load_model_wmm
from geoist.magmod.magnetic_model.loader_emm import load_model_emm
总会出现这个错误，没有_pymm。

Hi @igp-gravity, I found this package today and was a bit surprised to see so much code from Fatiando a Terra copied here without explicit acknowledgement and without our license and copyright notice in the source. While the BSD 3-clause license used in all our projects permits redistribution of the source code, you are required by the license to include the copyright notice and license terms along with the copied code. See https://github.com/fatiando/verde/blob/master/LICENSE.txt for example. It would be courteous if you included a notice in the documentation (docstrings) as well, though you are not required by the license to do so.

In fact, I would encourage you to not copy the code from projects like Verde here (of course, you can do so if you want and follow the license terms). Instead, installing and import verde as a dependency is the best way to do this. You wouldn’t copy the NumPy code into your repository, for example. This is not hard to do and users would get the benefit of the latest developments from Verde when we make new releases. There is a growing ecosystem of geophysics software in Python (fatiando, simpeg, gempy, pygimli) and making code that plays well with the existing packages is a great boost to everyone. geoist has some interesting functionality that would be a great complement to the existing tools without needing to try to include all of them in its own source. This also encourages contributions from experienced open-source developers, like myself and the rest of the Fatiando community who might find geoist useful.

If you have modifications to the library (Verde etc), you should contribute those back to the project so that all can benefit instead of keeping them here. We welcome new contributions and have a comprehensive guide for giving credit to contributors: https://github.com/fatiando/contributing/blob/master/AUTHORSHIP.md

If you need functionality from the fatiando package, please consider helping us port this to the new Harmonica package. We’re working hard to implement filters and modelling/inversion code but time is limited and we could use some help.

Thank you for writing open-source code and making your work public! It’s always great to see more of this. I hope you consider my suggestions above since open-source works best when it’s done as a community. If not, then please at least follow the BSD license terms.

Geoist有什么功能？

[它老是会在geoist目录下创建同样的文件，如果文件已经存在的话就报上面的错]