在这份报纸,因为到在如此的支持上定义的 C n 的从 C m 的任何合理 parametrization 是不适当的,在格子空间 Z m 的格子支持的一个班被发现内在地不适当。为如此的格子支持的不适当的索引被定义是所有单一的亚支持的规范的体积的 gcd。不适当的支持 S 的结构被分析,缩小的转变被构造转变 S 到合适的。为在不适当的支持 S 上定义的通用合理 parametrization RP,我们证明它的不适当的索引是 S 的不适当的索引并且为 RP 给一个合适的 reparametrization 算法。最后,为在不适当的支持上并且与数字系数定义的合理 parametrizations 的性质也被考虑。
In this paper, a class of lattice supports in the lattice space Zm is found to be inherently improper because any rational parametrization from Cm to Cm defined on such a support is improper. The improper index for such a lattice support is defined to be the gcd of the normalized volumes of all the simplex sub-supports. The structure of an improper support S is analyzed and shrinking transformations are constructed to transform S to a proper one. For a generic rational parametrization RP defined on an improper support S, we prove that its improper index is the improper index of S and give a proper reparametrization algorithm for RP. Finally, properties for rational parametrizations defined on an improper support and with numerical coefficients are also considered.