singular Jacobian encountered in bvp4c
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Hello,
I use "bvp4c" command for solving a ODE system,
I encounter the following problem:
??? Error using ==> bvp4c
Unable to solve The collocation equations - a singular Jacobian encountered
Is there someone who knows a method or solution. My code is, as follows:
function [phi90,phivarrho,phiteta]=phiFn(a,S90,Svarrho,coeff)
c1=coeff(1); c2=coeff(2); c3=coeff(3); c4=coeff(4); c5=coeff(5); c6=coeff(6); c7=coeff(7); c8=coeff(8); c9=coeff(9);
options=[];
xinit1= linspace(-a/2,0);
xinit2=linspace(0,a/2);
xinit=[xinit1,xinit2];
yinit=[1 ;0; 0; -c7*c1; 1; 0; 0; -c7*c1];
solinit= bvpinit(xinit,yinit);
sol = bvp4c(@ode1,@BCs,solinit,options,S90,Svarrho,coeff)
xint=sol.x;
yint=sol.y;
phi90=yint(1,:);
phivarrho=yint(5,:);
phiteta=-(2*phi90+phivarrho);
function odesys = ode1(x,y,region,S90,Svarrho,coeff)
c1=coeff(1); c2=coeff(2); c3=coeff(3); c4=coeff(4);
c5=coeff(5); c6=coeff(6); c7=coeff(7); c8=coeff(8);
c9=coeff(9);
switch region
case 1 % x in [-a/2 0]
odesys = [ y(2);y(3);y(4);
(c6*c3*y(3)+c7*c3*y(1)+c9*c3*y(7)-c8*c2*y(3)-
c8*c4*y(7))/(-c5*c3+c1*c8);
y(6);y(7);y(8);(-c6*c3*y(3)-c7*c1*y(1)-
c9*c1*y(7)+c5*c2*y(3)+c5*c4*y(7))/(-c5*c3+c1*c8)];
case 2 % x in [0 a/2]
odesys = [ y(2);y(3);y(4);
(c6*c3*y(3)+c7*c3*y(1)+c9*c3*y(7)-c8*c2*y(3)-
c8*c4*y(7))/(-c5*c3+c1*c8);
y(6);y(7);y(8);(-c6*c3*y(3)-c7*c1*y(1)-
c9*c1*y(7)+c5*c2*y(3)+c5*c4*y(7))/(-c5*c3+c1*c8)];
end
end
function res = BCs(YL,YR,S90,Svarrho,coeff)
res = [YL(1,1)-S90;
YR(1,1)-S90;
YL(1,2)-S90;
YR(1,2)-S90;
YL(2,1);
YR(2,1);
YL(2,2);
YR(2,2);
YL(5,1)- Svarrho;
YR(5,1)-YL(5,2);
YL(5,2)-YR(5,1);
YR(5,2)-Svarrho;
YL(6,1);
YR(6,1)-YL(6,2);
YL(6,2)-YR(6,1);
YR(6,2)];
end
end
thank you
1 Comment
Answers (2)
Zeynab Mousavi.K
on 28 Apr 2011
oooooooo i have the same problem with exactly the same error if you understood the answer please inform me and i will tell you any solution if i found
2 Comments
Amir K Neghab
on 17 Nov 2011
Hi,
Have you found the error? I think so.
How can you solve the " Singular Jacobian Error"
Walter Roberson
on 17 Nov 2011
Amir, did you follow the link in my Comment, and try the Singular option?
Zachary
on 22 Oct 2012
Being that there are no 1/x terms in your odes we need to see your coeff function to determine if it contributes to the singular jacobian.
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