Determine the location of max curvature for a set of data

• 绘制图形

x = linspace(-5,5,100);
y = exp(-x.^2) + sin(x/2);

figure(1)
subplot(131)
plot(x,y,'o');
grid on;

subplot(132)
d1 = diff(y,1)
plot(linspace(-5,5,length(d1)),d1)
grid on;


subplot(133)
d2 = diff(y,2)
plot(linspace(-5,5,length(d2)),d2)
grid on;
tightfig
% 
% pp = spline(x,y);
% p_der2 = fnder(pp,2);
% slm = slmengine(x,y)
% d = slmeval(x,slm,2);
% plot(x,d,'-')
% grid on

• 下载调用工具箱
  https://ww2.mathworks.cn/matlabcentral/fileexchange/24443-slm-shape-language-modeling?requestedDomain=zh

• 求全局最大、最小曲率及其位置

% 曲线拟合
pp = spline(x,y);


% 求最大曲率及其位置
[fppmax,fppmaxloc] = slmpar(pp,'maxfpp')
fppmax =
       1.0405
fppmaxloc =
      -1.2626
      
%求最小曲率及其位置
[fppmin,fppminloc] = slmpar(pp,'minfpp')
fppmin =
      -2.0011
fppminloc =
     0.050505