landmarks.py 文件源码

def precompute_kernels(self, q) :
        """
        Returns a tuple of kernel, kernel', kernel'' matrices at position q.
        """
        x = q.reshape((self.npoints, self.dimension))
        dists = squareform(pdist(x, 'sqeuclidean'))
        K = exp(- dists / (2* self.kernel_scale ** 2))

        return (  K, 
                - K / (2* self.kernel_scale ** 2), 
                  K / (4* self.kernel_scale ** 4))