init

FOTF Toolbox/glfdiff.m

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+function dy=glfdiff(y,t,gam)
+% glfdiff_mat - evaluation of O(h) GL derivatives with matrix algorithm 
+%
+%   dy=glfdiff_mat(y,t,gam)
+%
+%   y - the samples of the function handle of the original function
+%   t - the time vector
+%   gam - the fractional order
+%   dy - the fractional-order derivatives, or integrals if gam<0
+   
+% Copyright (c) Dingyu Xue, Northeastern University, China
+% Last modified 28 March, 2017 
+% Last modified 18 May, 2022 
+   arguments, y(:,1), t(:,1) double, gam(1,1) double, end
+   [y,h,n]=fdiffcom(y,t); w=[1,zeros(1,n-1)]; a0=y(1); dy(1)=0;
+   if a0~=0 && gam>0, dy(1)=sign(a0)*Inf; end
+   for j=2:n, w(j)=w(j-1)*(1-(gam+1)/(j-1)); end
+   for i=1:length(t), dy(i,1)=w(1:i)*y(i:-1:1)/h^gam; end
+end