Using ode 45 for the shooting method

Dear experts,

I'm given a system of ODE's that I am able to solve using "ode45" . The system contains several initial conditions, and I am mainly interested in one of them - "k" . I want to find the value of "k" for which one of the variables (which I shall call "u") is 0 at x=20.

I have tried the following ( I give only the important parts of the code):

1. function uTWENTY=check(k)

       [X,Y]=ode45(@... , [0 20] ,[... k ... ] ) 

       uTWENTY=Y(end,4); %assuming Y(:,4) = u 

   end

2. function shooting

       correctK=fzero(check,[0.001,1]);

%I want somewhere inside this interval 0.001,1] there must be a correct value of k

   end

Unfortunately, I always get the same error: "Reference to a cleared variable k"

Will someone please help me understand how to ask MATLAB to solve "check" inside the interval [0.001,1] (where the unknown is k)?

Thanks in advance!

Answer 1

[Jan]

Do you mean:

correctK = fzero(@check, [0.001, 1]);

[Johnson]

An Update : It worked ! (In addition to deleting the "clear all " at the start of the second function :) )

Thanks a lot !