07_01_49. timeseries 그래프에 linear regression trend line 추가

import pandas as pd
import numpy as np
from matplotlib import pyplot as plt
import matplotlib.pylab as plt2
import matplotlib.dates as mdates

plt2.rcParams["figure.figsize"] = (8,2.5)
fig, ax0 = plt.subplots()
ax0.set_xlabel('year_month')
ax0.tick_params(axis='x', labelrotation=45)
ax0.set_ylabel('y')
# ax0.set_ylim(400,1200)

x = np.arange(df['date'].size)
y = df['y']
fit = np.polyfit(x, y, 1 )
fit_fn = np.poly1d(fit)

ax0.plot( df['date'], fit_fn(x), 'r--')

ax0.plot( df['date'], df['y'], color='black' , label='총')

https://stackoverflow.com/questions/37337836/linear-regression-with-pandas-time-series