Numerical integration of 2‐D integrals based on local bivariate C1 quasi‐interpolating splines

In this paper cubature formulas based on bivariate C1 local polynomial splines with a four directional mesh [4] are generated and studied. Some numerical results with comparison with other methods are given. Moreover the method proposed is applied to the numerical evaluation of 2‐D singular integrals defined in the Hadamard finite part sense. Computational features, convergence properties and error bounds are proved.