Data preprocessing

[kokarevn]

1) Algorithm of stationaryization of time series consists of the following:

 - A log transformation of feature variables to make data as "normal" as possible and make the statistical analysis results from this data more valid.
 - Performed stationarization of time series by the differencing method with a shift equal to 1.

2) Data Plotting:

• Drawn stationar data graphs using the seaborn and matplotlib libraries.
• Estimated the Dickey-Fuller test to evaluate the stationarity degree.

[Gandolier]

Link to the code: https://colab.research.google.com/drive/1tmsa-w4ZdDBx4YoF5-hrPwkxPLgkFSqS?usp=sharing