“…In the last five decades, radial basis function (RBF) methods have gradually become an extremely powerful tool for scattered data. This is not only because they possess the dimensional independence and remarkable convergence properties (see, e.g., [1][2][3][4][5]), but also because a number of techniques, such as multipole (far-field) expansions [2,6], multilevel methods of compactly supported kernels [2,[7][8][9] and partition of unity methods [2,10,11], have been proposed to reduce both the condition number of the resulting interpolation matrix and the complexity of calculating the interpolant. These techniques are, of course, very important in practice, however, in contrast to the stability and efficiency, maybe the later question is the most crucial one for a general representation of functions, that is, how to accurately capture and represent the intrinsic structures of a target function, especially in high dimensional space.…”