predcor.m

various matlab programs to slove various problems

function [u,t]=predcor(a,b,at,bt,h,f,t0,u0,tf,pece,m)
p  = max(length(a),length(b)-1); pt = max(length(at),length(bt)); 
q  = max(p,pt); if length(u0) < q, break, end; 
t  = [t0:h:t0+(q-1)*h]; u = u0; y = u0; fe = eval(f); 
k  = q; 
for t = t0+q*h:h:tf
   ut = sum(at.*u(k:-1:k-pt+1))+h*sum(bt.*fe(k:-1:k-pt+1));
   y  = ut; foy = eval(f);
   uv = sum(a.*u(k:-1:k-p+1))+h*sum(b(2:p+1).*fe(k:-1:k-p+1));
   k = k+1;
   for j = 1:m
      fy = foy; up = uv + h*b(1)*fy; y  = up; foy = eval(f);
   end
   if (pece=='y' | pece=='Y')
      fe = [fe, foy];
   else
      fe = [fe, fy];
   end
   u = [u, up];
end
t = [t0:h:tf];