python - "Value Error: x and y must be same size"错误。多元线性回归

Question

import numpy as np
import matplotlib.pyplot as plt
import pandas as pd

dataset=pd.read_csv("Marketing_Data.csv")
X = dataset.iloc[:, :-1].values
y = dataset.iloc[:, -1].values

from sklearn.model_selection import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 1/3, random_state = 0)

from sklearn.linear_model import LinearRegression
regressor = LinearRegression()
regressor.fit(X_train, y_train)
lin_reg = LinearRegression()
lin_reg.fit(X,y)

y_pred = regressor.predict(X_test)
np.set_printoptions(precision = 2)
plt.scatter(X, y, color = 'red')
plt.plot(X, lin_reg.predict(X), color = 'blue')
plt.title("Sales")
plt.show()

我正在尝试编写多元线性回归。有 3 个自变量和 1 个因变量。我得到一个

Value Error: x and y must be same size

和一个空的 matplotlib 图。
回溯:

  File "||file path comes here||\untitled0.py", line 20, in <module>
    plt.scatter(X, y, color = 'red')

  File "C:\Anaconda\lib\site-packages\matplotlib\pyplot.py", line 2890, in scatter
    __ret = gca().scatter(

  File "C:\Anaconda\lib\site-packages\matplotlib\__init__.py", line 1438, in inner
    return func(ax, *map(sanitize_sequence, args), **kwargs)

  File "C:\Anaconda\lib\site-packages\matplotlib\cbook\deprecation.py", line 411, in wrapper
    return func(*inner_args, **inner_kwargs)

  File "C:\Anaconda\lib\site-packages\matplotlib\axes\_axes.py", line 4441, in scatter
    raise ValueError("x and y must be the same size")

Answer 1

plt.scatter 期望 x 和 y 的形状均为 (n, )，因此如果您的 X 是 2 维或更高维，它将不起作用。
由于您正在进行多元线性回归并且您的 X 有很多维度，因此您需要散点图以外的其他东西。 (或者只是选择 X 的一维作为绘图的 x 轴。)