稀疏表示高光谱异常检测算法python代码
时间: 2023-10-03 22:08:34 浏览: 54
稀疏表示高光谱异常检测算法的Python代码如下所示:
```python
import numpy as np
from sklearn.linear_model import OrthogonalMatchingPursuit
def sparse_rep(data, dictionary):
omp = OrthogonalMatchingPursuit(n_nonzero_coefs=5)
omp.fit(dictionary, data)
coef = omp.coef_
return coef
def anomaly_detection(data, dictionary):
coef = sparse_rep(data, dictionary)
residual = np.linalg.norm(data - np.dot(dictionary, coef))
return residual
# 假设有100个高光谱样本,每个样本有200个波段
spectra = np.random.rand(100, 200)
# 假设现在有20个正常样本,用来构建字典
normal_spectra = spectra[0:20, :]
# 构造字典
dictionary = np.transpose(normal_spectra)
# 假设现在有一个新的样本,用来检测是否异常
new_spectra = spectra[21, :]
# 异常检测
residual = anomaly_detection(new_spectra, dictionary)
if residual > threshold:
print('该样本为异常样本')
else:
print('该样本为正常样本')
```
上面的代码中,`sparse_rep`函数使用正交匹配追踪算法(Orthogonal Matching Pursuit)对数据进行稀疏表示,`anomaly_detection`函数计算新样本与字典的残差,并与事先设置的阈值进行比较,从而判断该样本是否为异常样本。