线性回归 - 图上的方程式 - Python

Question

嘿，我想做线性回归并创建一个图，其上也将是我的模型的方程。我有以下代码：

from sklearn.linear_model import LinearRegression

X = np.array((1,2, 3, 4))
Y = np.array((3, 1, 4, 5))

X = X.reshape((-1, 1))
model = LinearRegression().fit(X, Y)


plt.scatter(X, Y, color='g')
plt.plot(X, model.predict(X),color='k')

print(model.coef_[0], model.intercept_)

如何在我的绘图上自动写方程？

Answer 1

Text in Matplotlib Plots

Matplotlib has extensive text support, including support for mathematical expressions, truetype support for raster and vector outputs, newline separated text with arbitrary rotations, and unicode support.

来自official documentation以下命令用于在pyplot界面和面向对象API中创建文本：

pyplot API	OO API	description
text	text	Add text at an arbitrary location of the Axes.
annotate	annotate	Add an annotation, with an optional arrow, at an arbitrary location of the Axes.
xlabel	set_xlabel	Add a label to the Axes's x-axis.
ylabel	set_ylabel	Add a label to the Axes's y-axis.
title	set_title	Add a title to the Axes.
figtext	text	Add text at an arbitrary location of the Figure.
suptitle	suptitle	Add a title to the Figure.

from sklearn.linear_model import LinearRegression
import numpy as np
import matplotlib.pyplot as plt

X = np.array((1,2, 3, 4))
Y = np.array((3, 1, 4, 5))

X = X.reshape((-1, 1))
model = LinearRegression().fit(X, Y)

fig = plt.figure()
ax = fig.add_subplot()
plt.scatter(X, Y, color='g')
plt.plot(X, model.predict(X),color='k')
ax.text(1, 4, r'LR equation: $Y = a + bX$', fontsize=10)

print(model.coef_[0], model.intercept_)

剧情：