CALCULATIONS OF BIVARIATE SPLINES——Ⅰ. Truncated Powers and BM-Splines in S_2~1, (?)2 and S_4~2,(?)_2

Determining the lowest degree, dimensions and basis functions of btp (bivariate truncated power(s)) spaces with given smoothness requirements and establishing the calculation formulae of btp on a three-and four-direction mesh, we give the necessary and sufficient condition for the existence of the bivariate BM-spline in S_4~2, and the bivariate BM-spline in S_2~1, in terms of linear combinations of btp. The so-called "revolving around" teahnique is mentioned.     

CALCULATIONS OF BIVARIATE SPLINES——Ⅱ. BM-Splines in S_k~p. △_2, S_3~1, (?)_2 and S_4~2,(?)_2

Examining the B-coefficient relations between two adjacent s-simplicies with given smoothness requirements, we find a compromise technique between btp-coefficients and B-coefficients to calculate a bivariate locally supported spline, give another proof of the BM-splines in S_(100)(4d, 3d-1, △_2) and establish the BM-splines in S_2~1, and S_4,