python筆記：6.2.1.1單總體均值參數估計_活塞環直徑

 

# -*- coding: utf-8 -*-
"""
Created on Tue Jun 11 15:26:27 2019

@author: User
"""

# from 中國統計出版社 《Python數據分析基礎》

import numpy as np
#from scipy import stats
#import pandas as pd
#import statsmodels.api as sm

# 8只活塞的直徑
ar=np.array([74.001,74.005,74.003,74.001,
             74.000,73.998,74.006,74.002])

print("\n 總體均值 np.mean(ar)")
a_mean=np.mean(ar)
print(a_mean)

print("\n 總體方差 np.var(ar,ddof=0)")
a_var1=np.var(ar,ddof=0)
print(a_var1)

print("\n 樣本方差 np.var(ar,ddof=1)")
a_var2=np.var(ar,ddof=1)
print(a_var2)