ODE-matlab

Hello.

I want to solve this equation system:

x ̈ = q ( y ̇ B z − z ̇ B y ) m y ̈=−q (x ̇Bz−z ̇Bx) m z ̈= q (x ̇By −y ̇Bx) m x(0) = x0, y(0) = y0, z(0) = z0 x ̇(0) = v0,x, y ̇(0) = v0,y, z ̇(0) = v0,z.

and with B = [1 1 1]' and m=q=1.

When I look at the equation system it seems for me very complicated and I really don't have a clue how to solve this. But, here is my attempt so far:

function [dU]=ODE(t,U)
dU = zeros(size(U));
q=1;m=1;           

x(0)=1; % Can I assume what x(0),y(0),z(0) , x1(0),y2(0) and z3(0) should be?
y(0)=1; 
z(0)=1;
x1(0)=2;
y2(0)=2;
z3(0)=2;

v=[1;1;1];          
x=[2;2;2];          

B=[0;0;1];          

Tt=100;             
Tp=1;               
B=Tt*file1(x)+Tp*file2(v); 

x2=q./m*(diffy(y)*B(:,3)-diffy(z)*B(:,2))
y2=-q./m*(diffy(x)*B(:,3)-diffy(z)*B(:,1))
z2=q./m*(diffy(y)*B(:,3)-diffy(x)*B(:,1))

dy(1)= y(3)     
dy(2)= y(4)     
dy(3)=  ?        
dy(4)=  ?
dy(5)=  ?     
dy(6)=  ?

Can someone please, help me explain this?

Regards Cillian

[Cillian]

For some reason, I get the warning:

"The selected cell cannot be evaluated because it contains an invalid statement."

Why is that?

[Walter Roberson]

Are you attempting to execute code that has the question marks in it ??