拉普拉斯映射的基本思想是在高维空间中离得 很近的点投影到低维空间中的像也应该离得很近,最终求解归结到图拉普拉斯算子的广义特征值问题,本例为拉普拉斯调用函数,对于学习维数约简的同学或许有帮助.-The basic idea is the Laplace mapping from very near the point of projection in the high-dimensional space as low-dimensional space should be very close