K 表示绘图未正确显示

Question

我正在尝试可视化 K-Means clustering implementation on the Divorce dataset from UCI Machine Learning Repository 的结果。

我的代码如下：

import pandas as pd, seaborn as sns1
import matplotlib.pyplot as plt
from scipy import cluster
from sklearn.cluster import KMeans
from sklearn.model_selection import train_test_split

df = pd.read_csv('C:\Users\wundermahn\Desktop\code\divorce.csv')
y = df['Class']
X = df.drop('Class', axis=1)

X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42)

y_pred = KMeans(n_clusters=2, random_state=170).fit_predict(X_test)
plt.subplot(221)
plt.scatter(X_test[:, 0], X_test[:, 1], c=y_pred)
plt.title("Guess")

plt.show()

这在很大程度上受到了上述 hyperlink K-Means link 的影响。

我收到一个错误：

Traceback (most recent call last):
  File "c:\Users\wundermahn\Desktop\code\kmeans.py", line 25, in <module>
    plt.scatter(X_test[:, 0], X_test[:, 1], c=y_pred)
  File "C:\Python367-64\lib\site-packages\pandas\core\frame.py", line 2800, in __getitem__
    indexer = self.columns.get_loc(key)
  File "C:\Python367-64\lib\site-packages\pandas\core\indexes\base.py", line 2646, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 111, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 116, in pandas._libs.index.IndexEngine.get_loc
TypeError: '(slice(None, None, None), 0)' is an invalid key

我做错了什么？为什么我的切片是 None 类型，而我明明在向它传递数据？

Answer 1

plt.scatter 期望 x 和 y 为 array_like。显然，对于此函数，数据框不是数组。

如果您将 X 或 plt_scatter 的输入转换为 Numpy 数组，它应该可以工作。

import pandas as pd, seaborn as sns1
import matplotlib.pyplot as plt
from scipy import cluster
from sklearn.cluster import KMeans
from sklearn.model_selection import train_test_split
import numpy as np
df = pd.read_csv('divorce.csv', sep=';')
y = df['Class']
X = np.array(df.drop('Class', axis=1))

X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42)

y_pred = KMeans(n_clusters=2, random_state=170).fit_predict(X_test)
plt.subplot(221)
plt.scatter(X_test[:, 0], X_test[:, 1], c=y_pred)
plt.title("Guess")
plt.show()

K 表示绘图未正确显示

K Means plot not showing properly

python

matplotlib

k-means

pandas

scikit-learn