python金融正太var方差-协方差代码
import numpy as np
import pandas as pd
import scipy.stats as st
from pylab import mpl
mpl.rcParams["font.sans-serif"] = ["KaiTi"]
mpl.rcParams["axes.unicode_minus"] = False
stock_price = pd.read_excel("D:\python代码\\first\daorutry.xlsx",sheet_name="Sheet1",header =0,index_col=0)
stock_return = np.log(stock_price/stock_price.shift(1))
stock_return = stock_return.dropna()
a = stock_return.loc[:,"收盘/最新价"]
a_mean =a.mean()
b = "%.4f" % a_mean
print(b)
p = np.percentile(a, (1, 5, 10), interpolation='midpoint')
p = np.abs(p[1])
print(("%.4f")%p)
arf = float(input("请输入置信水平:"))
z = st.norm.ppf(q=1-arf)
z = np.abs(z)
P0 = 1000
N = int(input("请输入持有月份:"))
N = N*30
var = np.sqrt(N)*P0*(z*p-float(b))
print(var)