https://blog.csdn.net/Dax1n/article/details/70304316
https://buildmedia.readthedocs.org/media/pdf/pywavelets/stable/pywavelets.pdf 5.2.14节
https://blog.csdn.net/Dax1n/article/details/70304316
https://buildmedia.readthedocs.org/media/pdf/pywavelets/stable/pywavelets.pdf 5.2.14节