用麻雀搜索算法优化k-means聚类算法完整代码
时间: 2023-07-28 09:09:27 浏览: 133
当然,我可以帮您提供使用麻雀搜索算法优化k-means聚类算法的代码。下面是一个示例的完整代码:
```python
import numpy as np
class KMeans:
def __init__(self, n_clusters, max_iter=100):
self.n_clusters = n_clusters
self.max_iter = max_iter
def fit(self, X):
self.centroids = X[np.random.choice(range(len(X)), self.n_clusters, replace=False)]
for _ in range(self.max_iter):
clusters = self.assign_clusters(X)
new_centroids = self.update_centroids(X, clusters)
if np.allclose(self.centroids, new_centroids):
break
self.centroids = new_centroids
def assign_clusters(self, X):
clusters = []
for x in X:
distances = np.linalg.norm(x - self.centroids, axis=1)
cluster = np.argmin(distances)
clusters.append(cluster)
return np.array(clusters)
def update_centroids(self, X, clusters):
new_centroids = []
for i in range(self.n_clusters):
cluster_points = X[clusters == i]
centroid = np.mean(cluster_points, axis=0)
new_centroids.append(centroid)
return np.array(new_centroids)
class SparrowSearch:
def __init__(self, n_clusters, n_sparrows, max_iter=100, w=0.9, c1=2.0, c2=2.0):
self.n_clusters = n_clusters
self.n_sparrows = n_sparrows
self.max_iter = max_iter
self.w = w
self.c1 = c1
self.c2 = c2
def fit(self, X):
self.sparrows = X[np.random.choice(range(len(X)), self.n_sparrows, replace=False)]
self.best_centroids = None
self.best_cost = np.inf
for _ in range(self.max_iter):
self.update_centroids(X)
self.update_positions()
cost = self.calculate_cost(X)
if cost < self.best_cost:
self.best_centroids = self.centroids
self.best_cost = cost
def update_centroids(self, X):
kmeans = KMeans(self.n_clusters)
kmeans.fit(self.sparrows)
self.centroids = kmeans.centroids
def update_positions(self):
velocities = np.zeros_like(self.sparrows)
for i in range(self.n_sparrows):
r1 = np.random.random(self.sparrows.shape[1])
r2 = np.random.random(self.sparrows.shape[1])
velocities[i] = (self.w * velocities[i] +
self.c1 * r1 * (self.centroids[i] - self.sparrows[i]) +
self.c2 * r2 * (self.best_centroids[i] - self.sparrows[i]))
self.sparrows[i] += velocities[i]
def calculate_cost(self, X):
distances = np.linalg.norm(X[:, None] - self.centroids, axis=2)
cluster_assignments = np.argmin(distances, axis=1)
cost = 0
for i in range(self.n_clusters):
cluster_points = X[cluster_assignments == i]
cluster_distances = np.linalg.norm(cluster_points - self.centroids[i], axis=1)
cost += np.sum(cluster_distances)
return cost
# 示例使用鸢尾花数据集
from sklearn.datasets import load_iris
data = load_iris().data
kmeans = KMeans(3)
kmeans.fit(data)
sparrow_search = SparrowSearch(3, 10)
sparrow_search.fit(data)
print("K-means centroids:")
print(kmeans.centroids)
print("SparrowSearch centroids:")
print(sparrow_search.best_centroids)
```
这个代码示例中包含了两个类:`KMeans`和`SparrowSearch`。`KMeans`类实现了普通的k-means聚类算法,而`SparrowSearch`类使用麻雀搜索算法对k-means进行优化。
注意:这只是一个简单的示例代码,实际使用时可能需要根据具体问题进行适当的调整和改进。
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