B样条基函数的导数怎么求?答:简单说,导函数没有根,原函数至多有一个根.推而广之,如果f(x)在[a,b]连续,在(a,b)内n阶可导.并且f(x)在[a,b]有n+1个根:x0,x1,x2,xn,那么根据罗尔定理,f'(x)在(x0,x1),(x1,x2),,(xn-1,xn)内分别至少有一个根,从而在(a,b)内至少有n个根,同理f''(x)在(a,b)内...
B样条函数答:[SP,VALUES] = SPAPS(X,Y,TOL) returns the B-form and, if asked, the values at X, of a cubic smoothing spline f to the data X, Y.The smoothing spline approximates, at the data site X(j), the given data value Y(:,j), j=1:length(X). The data values may be...