Bivariate C1 Cubic Spline Spaces Over Even Stratified Triangulations

Huan-Wen Liu1, Don Hong2
1School of Mathematics and Applied Statistics, University of Wollongong, Wollongong
2Department of Mathematics, East Tennessee, State University, Johnson City

Tóm tắt

It is well-known that the basic properties of a bivariate spline space such as dimension and approximation order depend on the geometric structure of the partition. The dependence of geometric structure results in the fact that the dimension of a C 1 cubic spline space over an arbitrary triangulation becomes a well-known open problem. In this paper, by employing a new group of smoothness conditions and conformality conditions, we determine the dimension of bivariate C 1 cubic spline spaces over a so-called even stratified triangulation.

Tài liệu tham khảo

P. Alfeld, Bivariate splines and the four color problem, manuscript, http://www.math.utah.edu/alfeld/talks/S13/4CMP/s1.html (1998). P. Alfeld and L. L. Schumaker, The dimension of bivariate spline spaces of smoothness r for degree d ≥ 4r + 1, Const. Approx. 3, 189-197 (1987). P. Alfeld, B. Piper, and L. L. Schumaker, Minimally supported bases for spaces of bivariate piecewise polynomials of smoothness r and degree k ≥ 4r + 1, Computer Aided Geometric Design 4, 105-123 (1987). P. Alfeld, B. Piper, and L. L. Schumaker, Spaces of bivariate splines on triangulations with holes, J. Approx. Theory Appl. 3, 1-10 (1987). P. Alfeld, B. Piper, and L. L. Schumaker, An explicit basis for C1 quartic bivariate splines, SIAM J. Numer. Anal. 24, 891-911 (1987). Y. S. Chou, L. Y. Su, and R. H. Wang, The dimensions of bivariate spline spaces over triangulations, Int. Ser. Numer. Math. 75, Birkhäuser, Basel (1985), pp. 71-83. C. K. Chui and D. Hong, Swapping edges of arbitrary triangulations to achieve the optimal order of approximation, SIAM J. Numer. Anal. 34, 1472-1482 (1997). C. K. Chui and T. X. He, Bivariate C1 quadratic finite elements and vertex splines, Math. Comp. 54, 169-187 (1990). C. K. Chui and R. H. Wang, Multivariate spline spaces, J. Math. Anal. Appl. 94, 197-221 (1983). C. K. Chui and R. H. Wang, On smooth multivariate spline functions, Math. Comp. 47, 131-142 (1983). D. Diener, Instability in the dimension of spaces of bivariate piecewise polynomials of degree 2r and smoothness r, SIAM J. Numer. Anal. 27, 543-551 (1990). D. Diener, Geometry dependence of the dimension of spaces of piecewise polynomials on rectilinear partitions, Computer Aided Geometric Design 14, 43-50 (1997). J. B. Gao, On the dimension of the bivariate spline spacesS r 3r (Δ*),J. Mathematical Research and Exposition 14, 367-378 (1994). G. Heindl, Interpolation and approximation by piecewise quadratic C1-functions of two variables, in Multivariate Approximation Theory', W. Schempp and K. Zeller, eds., Birkhäuser, Basel (1979), pp. 146-161. D. Hong, Spaces of bivariate spline functions over triangulations, Approx. Theory and Appl. 7, 56-75. MR 92f:65016 (1991). D. Hong, Recent progress on multivariate splines, in Approximation Theory: In Memory of A. K. Varma, N. K. Govil et al., eds., Marcel Dekker, New York (1998), pp. 265-291. D. Hong and H. W. Liu, Some new formulation of smoothness conditions and conformality conditions for bivariate cubic splines, Computer and Mathematics with Application 40, 117-125 (2000). R. Q. Jia, Lower bounds on the dimension of spaces of bivariate splines, in Multivariate Approximation and Interpolation, W. Haussmann and K. Jetter, eds., Birkhäuser Verlag, Berlin (1990), pp. 155-165. H. W. Liu, An integral representation of bivariate splines and the dimension of quadratic spline spaces over stratified triangulations, Acta Math. Sinica 37, 534-543 (1994). H. W. Liu, The dimension of cubic spline space over stratified triangulations, J. Mathematical Research and Exposition 16, 199-208 (1996). C. Manni, On the dimension of bivariate spline spaces on generalized quasi-cross-cut partitions, J. Approx. Theory 69, 141-155 (1992). J. Morgan and R. Scott, A nodal basis for C1 piecewise polynomials of degree n ≥ 5, Math. Comp. 29, 736-740 (1975). J. Morgan and R. Scott, The dimension of piecewise polynomials, Manuscript (1977). M. J. D. Powell and M. A. Sabin, Piecewise quadratic approximations on triangles, ACM Trans. Math. Software 3, 316-325 (1977). L. L. Schumaker, On the dimension of spaces of piecewise polynomials in two variables, in Multivariable Approximation Theory, W. Schempp and K. Zeller, eds., Birkhäuser, Basel (1979), pp. 396-412. L. L. Schumaker, On super splines and finite elements, SIAM J. Numer. Anal. 26, 997-1005 (1989). X. Q. Shi, The singularity of Morgan-Scott triangulation, Computer Aided Geometric Design 8, 201-206 (1991). G. Strang, Piecewise polynomials and the finite elements method, Bull. Amer. Math. Soc. 79, 736-740 (1973). G. Strang, The dimension of piecewise polynomials, and one-sided approximation, in Proc. Conf. Numerical Solution of Differential Equations, Dundee 1973 pp. 144-152, Lecture Notes in Mathematics, no. 365, Springer-Verlag, New York (1974). R. H. Wang, The structural characterization and interpolation for multivariate splines, Acta Math. Sinica 18, 91-106 (1975). M. D. Ye, Some problems for the bivariate C1 cubic splines, Approx. Theory Appl. 4, 1-11 (1988).