python - KMeans "No handles with labels found to put in legend"的 3D 散点图图例错误

Question

我已经为 KMeans 模型绘制了 3D 散点图，该模型已适合 RFM 分析。我将 KMeans 模型标签用于“颜色”组。当我使用 legend() 时，它会弹出一个错误，“没有找到可放入图例的带有标签的句柄”

from mpl_toolkits.mplot3d import Axes3D     
%matplotlib notebook     

fig = plt.figure(figsize=(8, 6))     
ax = fig.add_subplot(111, projection='3d')      

xs = RFM['Recency'].dt.days      
ys = RFM['Frequency']      
zs = RFM['Value']      
ax.scatter(xs, ys, zs, s=50, alpha=0.6, c=final_model.labels_, cmap='rainbow')      

ax.set_xlabel('Recency(days)')      
ax.set_ylabel('Frequency')      
ax.set_zlabel('Value')      

ax.legend()      

Answer 1

您的代码存在的问题是您没有为分散点提供任何label，因此legend 没有任何作用。

遵循 Scatter plots with a legend matplotlib 网站上的教程，以下代码将数据随机化为三个“类”，并用图例绘制它们:

from matplotlib import pyplot as plt
import numpy as np

fig = plt.figure(figsize=(8, 6))
ax = fig.add_subplot(111, projection='3d')

xs = np.random.normal(0, 1, (20,))
ys = np.random.normal(0, 1, (20,))
zs = np.random.normal(0, 1, (20,))

labels = np.random.choice(["First", "Second", "Third"], (20,))

for lbl in np.unique(labels):
    indices = np.where(labels == lbl)
    x = xs[indices]
    y = ys[indices]
    z = zs[indices]
    print(x,y,z,lbl)
    ax.scatter(x, y, z, s=50, alpha=0.6, label=str(lbl), cmap='rainbow')

ax.legend()

plt.show()

结果是: