MATLAB - Need help storing values of previous iterations in a while loop

Ok. So I have a while loop that iterates for values of xcount and time. In the end, I need to plot all the xcount and time values. This should give me a simple harmonic plot. unfortunately, my while loop only stores the 'final' value for xcount and time. thus the plot produced is also wrong. Could someone please tell me where I have gone wrong. And how to fix it. Thanks

function [ X,t ] = spring( ks,rs,startx,d,m,c,tinc,atol,vtol )

X=startx;

t=0;

V=0;

a=0;

time = 0;

xcount=0;

F1=-ks(1)*(X-rs(1));

F2=ks(2)*(d-X-rs(2));

DampingF = c*V;

NetForce= F1 + F2 - DampingF;

a = (NetForce/m);

V = V + a*tinc;

t = t + tinc;

X = X + V*tinc;

xcount = [xcount X];

time = [time t];

while (abs(V) >= vtol) (abs(a) >= atol)

   F1=-ks(1)*(X-rs(1));

   F2=ks(2)*(d-X-rs(2));

   DampingF = c*V; 

   NetForce= F1 + F2 - DampingF;  

   a =(NetForce/m);

   V = V+(a*tinc);

   X = X + V*tinc;

   xcount = [0 X X];

   t = t + tinc;

   time = [0 tinc 2*tinc];

end

plot(xcount,time);

xlabel('x');

ylabel('Time');

end

Answer 1

[David Sanchez]

I think your while loop should go like this:

    while (abs(V) >= vtol) && (abs(a) >= atol)
       F1=-ks(1)*(X-rs(1));  
       F2=ks(2)*(d-X-rs(2));  
       DampingF = c*V;   
       NetForce= F1 + F2 - DampingF;    
       a =(NetForce/m);  
       V = V+(a*tinc);  
       X = X + V*tinc;  
       xcount = [xcount X];  
       t = t + tinc;  
       time = [time t];  
    end

[Jennet C JB]

thanks a lot David!!

yes I did try this, but once again this while loop only stores the final value of X and t in the workspace. I want the value after each iteration to be stored in a matrix.

So if I wanted to call the values of X and t in a future function, i wont be able to do this, since they are not the matrices that I need.