Error Using "bvp4c" - "a singular Jacobian encountered"

Hi,

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

function bvp5
xlow=0; xhigh=1;
solinit = bvpinit(linspace(xlow,xhigh,100),[1 -1]);
sol = bvp4c(@bvp5ode,@bvp5bc,solinit);
xint = linspace(xlow,xhigh);
Sxint = deval(sol,xint);
plot(xint,Sxint(1,:))

function dydx = bvp5ode(x,y)
dydx = [ y(2) (-1-y(2)/x)];

function res = bvp5bc(ya,yb)
res = [ ya(1)-1  yb(2) ];

And I get an error involving "a single Jacobian encountered". It seems to plot fine if I use:

function dydx = bvp5ode(x,y)
  dydx = [ y(2) (-1-y(2))];

I attached the differential equation I'm trying to solve as a picture, where "T" is y and "r" is x in the code above.

Thanks

[MOSLI KARIM]

function bvp5

xlow=0.00001; xhigh=1;

solinit = bvpinit(linspace(xlow,xhigh,100),[1 -1]);

sol = bvp4c(@bvp5ode,@bvp5bc,solinit);

xint = linspace(xlow,xhigh);

Sxint = deval(sol,xint);

plot(xint,Sxint(1,:))

function dydx = bvp5ode(x,y)

dydx = [ y(2) (-1-y(2)/x)];

function res = bvp5bc(ya,yb)

res = [ ya(1)-1 yb(2) ];

Answer 1

[Torsten]

The general solution of your equation is

y(x)=c1*log(x)+c2-x^2/4

with c1, c2 to be determined from the boundary conditions.

Now you can easily see that for the boundary conditions you want to prescribe, your equation does not have a solution.

Best wishes

Torsten.