[Study Notes] Chapter 3 of Machine Learning in Xigua Book: Logistic Regression Classification Prediction of South African Male Heart Disease (2)

(The handwritten formula was uploaded several times but could not be uploaded.)
The following is an example of logistic regression for male heart disease in South Africa:

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The traditional logistic regression code should add the offset to X, and then add 1 to the first position of weights to facilitate matrix operations. I calculate it separately here.

import pandas as pd
import numpy as np
import random
import matplotlib.pyplot as plt
"""
强烈建议一步一步来，每一步看看输出的结果是不是自己想要的。
"""
#载入数据南非男性心脏病数据
SAHeart_df = pd.read_csv('SAHeart.csv')
SAHeart_df['famhist'] = pd.get_dummies(SAHeart_df['famhist'])#把类型变量famihst变成哑变量


#获得X，Y
#选择特征X
X = (SAHeart_df[['famhist','sbp','tobacco','ldl','adiposity','typea','obesity','alcohol','age']])
Y = np.array(SAHeart_df[['chd']])

#归一化特征
cols_to_Normal = ['sbp','tobacco','ldl','adiposity','typea','obesity','alcohol','age']
X_new = X[cols_to_Normal]
X_new = X_new[cols_to_Normal].apply(lambda rec:(rec