本次作業的資料是從中央氣象局網站下載的真實觀測資料，希望大家利用linear regression或其他方法預測PM2.5的數值。

作業使用豐原站的觀測記錄，分成train set跟test set，train set是豐原站每個月的前20天所有資料。test set則是從豐原站剩下的資料中取樣出來。

train.csv：每個月前20天的完整資料。

test_X.csv：從剩下的10天資料中取樣出連續的10小時為一筆，前九小時的所有觀測數據當作feature，第十小時的PM2.5當作answer。一共取出240筆不重複的test data，請根據feauure預測這240筆的PM2.5。

https://inclass.kaggle.com/c/ml2017-hw1-pm2-5/

https://drive.google.com/file/d/0B8Si647wj9ZoelM4RktXZU1BbkE/view?usp=sharing

http:https://stackoverflow.com/questions/273192/how-to-check-if-a-directory-exists-and-create-it-if-necessary

http:https://stackoverflow.com/questions/1303347/getting-a-map-to-return-a-list-in-python-3-x

http:https://aimotion.blogspot.tw/2011/10/machine-learning-with-python-linear.html

https://docs.scipy.org/doc/numpy/reference/generated/numpy.concatenate.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.reshape.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.swapaxes.html
https://docs.scipy.org/doc/numpy/reference/arrays.indexing.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.square.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.vsplit.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.lstsq.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.savetxt.html
https://docs.scipy.org/doc/numpy/reference/generated/numpy.random.permutation.html

https://docs.scipy.org/doc/numpy/reference/generated/numpy.dot.html
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.matmul.html
http:https://stackoverflow.com/questions/34142485/difference-between-numpy-dot-and-python-3-5-matrix-multiplication

http:https://cpmarkchang.logdown.com/posts/275500-optimization-method-adagrad

https://en.wikipedia.org/wiki/Feature_scaling
https://www.coursera.org/learn/machine-learning/lecture/xx3Da/gradient-descent-in-practice-i-feature-scaling
http:https://sebastianraschka.com/Articles/2014_about_feature_scaling.html

http:https://math.mit.edu/~gs/linearalgebra/ila0403.pdf