MATLAB B样条拟合与求导可视化

% 输入数据 x = [0.052978, 0.104531, 0.15, 0.2, 0.252107]; y = [-0.463242, -0.275594, -0.131297, 0.0025, 0.110002];

% B样条拟合 t = 1:length(x); tq = 1:0.01:length(x); sp = spapi(t,x,y); yq = fnval(sp, tq);

% 画出散点图和B样条拟合曲线 figure; plot(x,y,'o',tq,yq); legend('Data','B-Spline Fit'); xlabel('x'); ylabel('y');

% 求导后画出曲线 yp = fnder(sp,1); yqp = fnval(yp, tq); figure; plot(tq,yqp); xlabel('x'); ylabel('y')