信号处理中的旋转不变子空间法，部分实现了追踪测速迭代松弛算法，是学习PCA特征提取的很好的学习资料，包括随机梯度算法，相对梯度算法，通过虚拟阵元进行DOA估计。- Signal Processing ESPRIT method, Partially achieved tracking speed iterative relaxation algorithm, Is a good learning materials to learn PCA feature extraction, Including stochastic gradient algorithm, the relative gradient algorithm, Conducted through virtual array DOA estimation.