0424机器学习使用时间序列

import datetime
import numpy as np
import pandas as pd
# 时间序列
pd.date_range(datetime.datetime(2016,1,1),periods=31)
pd.date_range(datetime.datetime(2019,2,1),periods=28)
pd.date_range("2019-1-1", periods = 28)
ts1 = pd.Series(np.arange(31), index = pd.date_range("2019-1-1", periods = 31))
ts1["2019-1-3"]
ts1.index[2]
ts1.index[2].year,ts1.index[2].month,ts1.index[2].week,ts1.index[2].weekday()

import numpy as np

def sigmod(x):
    return 1/(1+np.exp(-x))

def softmax(x):
    exp_sum = np.sum(np.exp(x))
    return np.exp(x)/exp_sum

sigmod_test = np.array([1 , 2])
softmax_test = np.array([100, 200, 300, 400])
sigmod(sigmod_test)
softmax(softmax_test)
def softmax(x):
    sum_exp = np.sum(np.exp(x-np.max(x)))
    return np.exp(x-np.max(x))/sum_exp
softmax_test = np.array([1000, 2000, 3000, 4000])
softmax_test = np.array([100, 200, 300, 400])
softmax(softmax_test)