http://www.scipy-lectures.org
https://docs.scipy.org/doc/numpy/user/quickstart.html

helloworld

• Q: How to transpose an array? — A: A.T, https://stackoverflow.com/questions/5954603/transposing-a-numpy-array, https://lihan.me/2018/01/numpy-reshape-and-transpose/
• Q: flatten vs rival vs reshape((-1,)) — A: https://stackoverflow.com/questions/28930465/what-is-the-difference-between-flatten-and-ravel-functions-in-numpy, https://stackoverflow.com/questions/28837312/what-is-the-difference-between-flatten-and-ravel-in-numpy

argsort()
vstack()
asmatrix()

arange https://docs.scipy.org/doc/numpy/reference/generated/numpy.arange.html
hstack https://docs.scipy.org/doc/numpy/reference/generated/numpy.hstack.html