A shape preserving quasi-interpolation operator based on a new transcendental RBF

Abstract

It is well-known that the univariate Multiquadric quasi-interpolation operator is constructed based on the piecewise linear interpolation by |x|. In this paper, we first introduce a new transcendental RBF based on the hyperbolic tangent function as an smooth approximant to φ(r) = r with higher accuracy and better convergence properties than the MQ RBF √ r 2 + c 2 . Then the Wu-Schaback's quasi-interpolation formula is rewritten using the proposed RBF. It preserves convexity and monotonicity. We prove that the proposed scheme converges with a rate of O(h 2 ). So it has a higher degree of smoothness. Some numerical experiments are given in order to demonstrate the efficiency and accuracy of the method.