Xin Yang: Kernel Independent Treecode Accelerated Kernel Smoothing

A kernel-independent treecode (KITC) is presented for fast summation of particle interactions. A regular treecode algorithm computes particle-cluster or cluster-cluster interactions instead of particle-particle interactions. The KITC uses barycentric Lagrange interpolation instead for the far-field approximation when particle and cluster are well-separated. It reduces the operation count and therefore it is more efficient.