MATLAB: Error using bvp4c (singular jacobian encountered)

bvp4c

How can I find the error in this MATLAB's script?
Script one: perfiles_thiele
clc; clear;
R=3;%input('Radio de particula en mm, R: ');
%%BVP solution problem
C0=2E-4;
dCdr0=0.016;
solinit = bvpinit(linspace(0,R,100),[C0 dCdr0]); 
sol = bvp4c(@model,@ex1bc,solinit);
   r =sol.x;
   C=sol.y(1,:);
   v=sol.y(2,:);
TWO:
function F =model(r,Y)
R=3;
Thiele =1;
   C=Y(1);
   v=Y(2);
dCdr= v;      
dvdr= (-2/r)*v + C*9*Thiele^2/R^2;
F = [dCdr; dvdr];
end
THREE:
function res = ex1bc(ya,yb) 
Cs=2E-6;
dCdr=0;
res = [ ya(1) - Cs 
        yb(2) - dCdr];
end
When I run the script one throws me the error:
Error using bvp4c (line 251)
Unable to solve the collocation equations -- a singular Jacobian encountered.
Error in perfiles_thiele (line 19)
 sol = bvp4c(@model,@ex1bc,solinit);
I appreciate help to know if the problem is the definition of [C0 dCdr0] or if it is because I have some error in my BVP system.
Thanks!

Best Answer

Don't start at r = 0, but at r = a small number.
Best wishes
Torsten.
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