Some performances of local bivariate quadratic C^1 quasi-interpolating splines on non uniform type-2 triangulations

We investigate spline quasi-interpolants defined by C^1 bivariate quadratic B-splines on nonuniform type-2 triangulations and by discrete linear functionals based on a fixed number of triangular mesh-points either in the support or close to the support of such B-splines. We show they can approximate a real function and its partial derivatives up to an optimal order and we derive local and global upper bounds. We also present some numerical and graphical results.