Bivariate quartic spline spaces and quasi-interpolation operators

In this paper, we study two bivariate quartic spline spaces S 4 3 , 2 ( Δ mn ( 2 ) ) and S 4 2 , 3 ( Δ mn ( 2 ) ) , and present two classes of quasi-interpolation operators in the two spaces, respectively. Some results on the operators are given.