pyqt_data_analysis/libdataanalysis/kmeans/demo.py

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2024-06-08 19:26:36 +08:00
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from k_means import KMeans
data = pd.read_csv('../data/iris.csv')
iris_types = ['SETOSA','VERSICOLOR','VIRGINICA']
x_axis = 'petal_length'
y_axis = 'petal_width'
plt.figure(figsize=(12,5))
plt.subplot(1,2,1)
for iris_type in iris_types:
plt.scatter(data[x_axis][data['class']==iris_type],data[y_axis][data['class']==iris_type],label = iris_type)
plt.title('label known')
plt.legend()
plt.subplot(1,2,2)
plt.scatter(data[x_axis][:],data[y_axis][:])
plt.title('label unknown')
plt.show()
num_examples = data.shape[0]
x_train = data[[x_axis,y_axis]].values.reshape(num_examples,2)
#指定好训练所需的参数
num_clusters = 3
max_iteritions = 50
k_means = KMeans(x_train,num_clusters)
centroids,closest_centroids_ids = k_means.train(max_iteritions)
# 对比结果
plt.figure(figsize=(12,5))
plt.subplot(1,2,1)
for iris_type in iris_types:
plt.scatter(data[x_axis][data['class']==iris_type],data[y_axis][data['class']==iris_type],label = iris_type)
plt.title('label known')
plt.legend()
plt.subplot(1,2,2)
for centroid_id, centroid in enumerate(centroids):
current_examples_index = (closest_centroids_ids == centroid_id).flatten()
plt.scatter(data[x_axis][current_examples_index],data[y_axis][current_examples_index],label = centroid_id)
for centroid_id, centroid in enumerate(centroids):
plt.scatter(centroid[0],centroid[1],c='black',marker = 'x')
plt.legend()
plt.title('label kmeans')
plt.show()