Question

高分求一道编程题，c++代码怎么写。

Let S be the cubic spline function that interpolates f (x) = (x^2 + 1)^−1 at 41 equally
spaced knots in the interval [−5, 5]. Evaluate S(x)− f (x) at 101 equally spaced points
on the interval [0, 5].
用matlab 写也ok

Answer 1

matlab自带spline函数进行三次样条拟合：

x = linspace(-5, 5, 41);
xx = linspace(0, 5, 101);

f = 1./(x.^2+1);
f2 = 1./(xx.^2+1);
S = spline(x, f, xx);

plot(xx, f2, 'o', xx, S);

S-f2

Answer 2

帮顶。
数学函数啊，迷糊