python笔记：7.3 协方差分析（分析各种因素对笔记本销售额的影响）

 

# -*- coding: utf-8 -*-
"""
Created on Tue Jul  9 15:27:58 2019

@author: User
"""

# 《Python数据分析基础》中国统计出版社

import numpy as np
from scipy import stats
import pandas as pd
import statsmodels.api as sm
import statsmodels.formula.api as smf
import matplotlib.pyplot as plt
from statsmodels.stats.multicomp import pairwise_tukeyhsd
from statsmodels.graphics.api import interaction_plot
from matplotlib.font_manager import FontProperties
myfont=FontProperties(fname='data\msyh.ttc')

sale_points = pd.read_csv(u'data\\ch7\\sale_points.csv',encoding = "gbk")

sale_points['market'] = sale_points['market'].astype('category')
sale_points['market'].cat.categories=['market 1', 'market 2',
        'market 3']

sale_points['warranty'] = sale_points['warranty'].astype('category')
sale_points['warranty'].cat.categories=['1 years', '3 years']

print(sale_points.head())

formula = 'sales ~ points + C(market) * C(warranty)'
sale_points_anova_cov = sm.stats.anova_lm(smf.ols(formula, 
                                                  data = sale_points).fit())  # dc_sales_est 是一个模型对象
print(sale_points_anova_cov)

运行：

     market warranty  sales  points
0  market 1  1 years   26.0     1.8
1  market 1  1 years   22.0     1.1
2  market 1  1 years   21.8     0.9
3  market 1  1 years   33.1     2.2
4  market 2  1 years   22.0     2.0
                         df      sum_sq     mean_sq          F        PR(>F)
C(market)               2.0  593.160833  296.580417  56.984051  2.903413e-08
C(warranty)             1.0  512.450417  512.450417  98.460650  1.734504e-08
C(market):C(warranty)   2.0  167.155833   83.577917  16.058404  1.211601e-04
points                  1.0  196.523934  196.523934  37.759505  1.079351e-05
Residual               17.0   88.478566    5.204622        NaN           NaN