Closed fractal interpolation surfaces (Q860555)

Based on the construction of bivariate fractal interpolation surface, the authors introduce, in Section 4, closed spherical fractal interpolation surfaces. The interpolation takes place in spherical coordinates and with the transformation to Cartesian coordinates a closed surface arises. There are given conditions needed for this construction (Theorem 3) and some theorems (in Section 5) about their Hausdorff and box-counting dimension are proved. In Section 6 the authors consider the problem of approximation of some given closed surface.