Error using bvp4c (singular jacobian encountered)

Hi,

I'm trying to run the following code, but keep running into an error:

E,I, F, and all other parameters below are constant and defined before running this solver.

 init=bvpinit(0:0.01:1,u1);
 sol = bvp4c(@(sig,u)odefun(sig,u,s_obj,x_obj,y_obj,theta_obj,theta0,F,E,I,x(1),y(1)),...
             @(uinitial,u1)bc(uinitial,u1,s_obj,x0,y0,theta_obj,theta0,F,E,I,x1,y1),...
             init);
         
         
function du=odefun(sig,u,s_obj,x_obj,y_obj,theta_obj,theta,F,E,I,x,y) 
    f=sqrt(F(1)^2+F(2)^2);  
    du(1)= s_obj*cos(theta);
    du(2)= s_obj*sin(theta);
    du(3)= s_obj*((g_tag(s_obj,theta)*h_taggaim(s_obj,theta)-h_tag(s_obj,theta)*g_taggaim(s_obj,theta))...
           /((g_tag(s_obj,theta)^2)+(h_tag(s_obj,theta))^2)^(3/2))...
           +(s_obj*f)/(E*I)*((x_obj-x)*cos(theta_obj)+(y_obj-y)*sin(theta_obj));
    
    
     du(4)= 0;
     du(5)= 0; 
     du(6)= 0; 
     du(7)= 0;     du=du';
end 

function res=bc(u0,u,s_obj,x0,y0,theta_obj,theta0,F,E,I,x1,y1)
    res=[u0(1)-x0
         u0(2)-y0
         u0(3)-theta0
         u(1)-x1
         u(2)-y1
         u(6)-theta_obj
         u(7)-s_obj]';
end 

function a=g_tag(s_obj,theta)                              
    a=s_obj*cos(theta) ;
end 

function b=g_taggaim(s_obj,theta)
b=-s_obj*sin(theta);                             
end

function aa=h_tag(s_obj,theta)
   aa=s_obj*sin(theta);
end 

function bb=h_taggaim(s_obj,theta)
  bb=s_obj*cos(theta);
end

Thanks!

[darova]

Can you show original equations and initial/boundary conditions?

[Karin Dekel]

r_pole, x_cen and y_cen are parameters

[Stephan]

Please provide the constants and all the other code that is needed to reproduce the error.

[Karin Dekel]

L=20; E=3
r_pole = 1
x_cen=10; y_cen=5

i'm trying to use the simpleset constants to first make bvp4c work for me, than i'll change them. so i'm currently using:

f=0
s_obj= 10
theta_obj=0

for these the bc are:

x0,y0,theta0=0; 
x1=10; y1=4,theta1=0;

thanks!

[darova]

PLease provide values for these variables

sig,u,s_obj,x_obj,y_obj,theta_obj,theta0,F,E,I

[Karin Dekel]

sig goes from 0 to 1

u is a 7x1 vect,

uinitial=[x0,y0,theta0,f,theta_obj,s_obj] (all above)

u1=[x1,y1,theta1,f,theta_obj,s_obj]

[darova]

Can't run without these values

[Karin Dekel]

sorry about that. too many parameters..

x_obj=10, y_obj=0

F=0.02

E=3

I=0.785

x(1)=x1=0, y(1)=y1=0

[Stephan]

Karin, we could dicuss this here for the next years... F should be a vector of length 2, there are also other issues. Why not just post the complete code that you use and that produces the error? Why are you making it that hard?

[Karin Dekel]

well, there was no intention of making this hard.

i will delete this and open a new question where i'll include the whole file.

thank you