Help on eigenvector plot

Hello forum,

I am trying to plot the eigenvector of my dataset. This is my code

X = 0:0.01:1; Y = 5*X+randn(size(X)); Z = 0:0.005:0.5;

A = cat(1,X,Y,Z);

c = A*A.';

[vec,val] = eig(c);

plot3(A(1,:),A(2,:),A(3,:),'ro'); hold on

%sc_vec = vec*val;

z = zeros(1,3); plot3([z;vec(1,:)],[z;vec(2,:)],[z;vec(3,:)],'k')

axis equal grid on

If I were to use the scaled vectors, it would look like the figure below.

Can anyone help me on this ?