多分类感知器算法的python实现
时间: 2023-07-26 10:47:14 浏览: 121
多分类感知器算法的Python实现可以通过构建多个二分类感知器来实现。以下是一个简单的多分类感知器算法的Python实现示例:
```python
import numpy as np
class MultiPerceptron:
def __init__(self, n_features, n_classes, learning_rate=0.01, n_epochs=100):
self.n_features = n_features
self.n_classes = n_classes
self.learning_rate = learning_rate
self.n_epochs = n_epochs
self.weights = np.zeros((n_classes, n_features))
self.biases = np.zeros(n_classes)
def predict(self, X):
scores = np.dot(X, self.weights.T) + self.biases
return np.argmax(scores, axis=1)
def fit(self, X, y):
for epoch in range(self.n_epochs):
for i in range(X.shape[0]):
scores = np.dot(X[i], self.weights.T) + self.biases
y_pred = np.argmax(scores)
if y_pred != y[i]:
self.weights[y[i]] += self.learning_rate * X[i]
self.biases[y[i]] += self.learning_rate
self.weights[y_pred] -= self.learning_rate * X[i]
self.biases[y_pred] -= self.learning_rate
```
其中,`n_features`为特征数,`n_classes`为类别数,`learning_rate`为学习率,`n_epochs`为迭代次数。`weights`为权重矩阵,`biases`为偏置向量,可通过`fit`方法进行训练,通过`predict`方法进行预测。
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