Error using bvp4c (singular jacobian encountered)

1 次查看（过去 30 天）

显示更早的评论

Karin Dekel 2020-5-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/534593-error-using-bvp4c-singular-jacobian-encountered

关闭： Karin Dekel 2020-6-3

在 MATLAB Online 中打开

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!

10 个评论
显示 8更早的评论隐藏 8更早的评论

Stephan 2020-6-3

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 2020-6-3