why i got this error?

Unexpected error

 function dFdx=funode(x,F)
global Lamda
global K1
global P
     dFdx=[F(2) ; -K1*P+F(1)*Lamda^2];

 function res=myfunbc(Fa,Fb)
global P
     res=[Fa(1) ;  Fb(1)-P];

 solinit=bvpinit(linspace(0,l,2),[1 0]);

     sol = bvp4c(@funode,@myfunbc,solinit);

     x = linspace(0,l);

     F = deval(sol,x);

After that i have an error The derivative function ODEFUN should return a column vector of length 2. why?

[Walter Roberson]

http://www.mathworks.co.uk/matlabcentral/answers/43073-a-guide-to-tags

Answer 1

[James Tursa]

Make it a column vector as requested:

dFdx=[F(2) ; -K1*P+F(1)*Lamda^2];

[Nadim Mhanna]

still the same error

[James Tursa]

What about the other function:

res=[Fa(1) ;  Fb(1)-P];

[Nadim Mhanna]

i did corrected both but didn't work

[Steven Lord]

What is the size of each of the variables K1, P, and Lamda?

[Nadim Mhanna]

They are constants i.e. k1=5 Lamda=13 P=252

[Walter Roberson]

Where is the value of P coming from in your lines

 function res=myfunbc(Fa,Fb)

     res=[Fa(1)   Fb(1)-P];

You are not using the form of "function" that would allow P to be a shared variable.

[Nadim Mhanna]

I did it by entering global P

[Nadim Mhanna]

For all the variables I put the global value that i did assign but still not working

[Walter Roberson]

When you use a global variable, it is not uncommon for the global variable to turn out to be empty at the time it is used.

http://www.mathworks.com/help/matlab/math/parameterizing-functions.html

[Nadim Mhanna]

okay got it Thanks all

[Jan]

@Nadim Mhanna: Please do not use flags to mark a "best answer". Flagging is thought to inform admins and editors, that a contribution needs attention, because it violates the terms of use, e.g. by rudeness.