为什么我看不到回归线？

Question

我已经为回归线编写了这段代码，但该线没有显示：

import pandas as pd

import matplotlib.pyplot as plt

import numpy as np

from scipy import stats

data=pd.read_csv("NHANES.csv")

correlation = data['BMI'].corr(data['Waist'])

print(f"Korrelationskoeffizient: {correlation}")

slope, intercept, r_value, p_value, std_err = stats.linregress(data['BMI'], data['Waist'])

regression_line = slope * data['BMI'] + intercept

plt.scatter(data['BMI'], data['Waist'], label='Streudiagramm')

plt.plot(data['BMI'], regression_line, color='red', label='Regressionsgerade')

plt.xlabel('BMI')

plt.ylabel('Waist')

plt.legend()

plt.show()

相关性为0.9

我只有散点图，没有线条

Answer 1

检查截距的变量类型。这是对我有用的代码：

import matplotlib.pyplot as plt
import numpy as np

price = [2.50, 1.23, 4.02, 3.25, 5.00, 4.40]
sales_per_day = [34, 62, 49, 22, 13, 19]
slope, intercept = np.polyfit(price, sales_per_day, 1)
regression_line = [slope * x + intercept for x in price]
print(type(regression_line) # this is list in this example

plt.scatter(price, sales_per_day, label='Scatter Plot')
plt.plot(price, regression_line, color='red', label='Regression Line')
plt.xlabel('Price')
plt.ylabel('Sales per Day')
plt.legend()
plt.show()