In fact, each B-spline basis function is non-zero on a few adjacent subintervals and, as a result, B-spline basis functions are quite local. Let U be a set of m + 1 non-decreasing numbers, u. The knots can be considered as division points that subdivide the interval [ u. To define B-spline basis functions, we need one more parameter, the degree of these basis functions, p. The i-th B-spline basis function of degree p, written as N. The above is usually referred to as the Cox-de Boor recursion formula. This definition looks complicated; but, it is not difficult to understand.
In 1989, the Griswold family wasn't so lucky in National Lampoon's Christmas Vacation, the third movie in a franchise that included 1983's inaugural Vacation, 1985's European Vacation and 1997's Vegas Vacation..
After appearing in 1983's National Lampoon's Vacation, Randy Quaid reprised his as role Cousin Eddie in Christmas Vacation. Cousin Eddie was so popular that Quaid even got his own spin-off in the made-for-TV movie, National Lampoon's Christmas Vacation 2: Cousin Eddie's Island Adventure.