Vector output from a function

Working on a projectile motion problem. I am trying to get x_dist and y_height vectors as outputs from my function so that I can then graph them. When I run my function it tells me that the variable x_dist does not exist even though it is in my function. Any help would be appreciated!

function [x_dist,y_height]=projectile(V_int,theta)
dt=1; %seconds
w=3; %kg
k=0.32;
g=9.81; %m/s^2
i=1;
y=0;
while y>0
    a_y(i)=w*g-V_int*k;
    a_x(i)=-V_int*k;
    v_y(i)=(V_int*sin(theta))+(a_y(i)*dt);
    v_x(i)=(V_int*cos(theta))+(a_x(i)*dt);
    x_dist(i)=(V_int-v_x(i))/1;
    y_height(i)=(V_int-v_y(i))/1;
    V_int=v_x(i);
    V_int=v_y(i);
    i=i+1;
    dt=dt+1;
end
pause(0.5);
comet(x_dist,y_height);
end

Answer 1

[Stephan]

Hi,

you set y=0. one line later you start a while loop, that is valid as long as y>0. This can not work. For this reason xdist is not there, because the while loop stopps the same moment it starts. xdist is defined inside the while loop.

Best regards

Stephan

Answer 2

[Walter Roberson]

You initialize y = 0. You have while y>0 . But 0>0 is false, so the body of your while loop is never done, and nothing was ever assigned to x_dist or y_height.

Note: you also do not assign to y in the loop, so if the loop did ever get started, then it would not stop.