ode45 - to a matrix

Hello.

I got another problem again. I want to get what ode45 returns to U:s first column of x-values, y-values and z-values. And the third to sixth rows should be the speeds in x-,y- and z-direction. But I have not succed to do that, can someone please tell me what I am doing wrong here.

Here is my code:

function f=magnet(~,B) 
m=1;q=1;               
a=1; b=0; c=0; 
f=[(q/m*(b*B(3)-c*B(2)))
    (-q/m(a*B(3)-c*B(1)))
    q/m*(a*B(2)-b*B(1))];

x0=[1 0 0]';        
v0=[0 1 0]';       
u0=[x0;v0];         

[~,U]=ode45(magnet,[0,6],u0); 

U= zeros(6,3);      
U(:, 1) = 1;        
U(:, 2) = 2;        
U(:, 3) = 3;        

figure(1);
title('Homogentmagnetfalt')
legend('x-axeln', 'y-axeln')
xlabel('x-axeln')
ylabel('y-axeln')
plot3(U(:,1),U(:,2),U(:,3)) 

hold on                     

end

Thanks Regards Cillian