my equation won't update

I have a function that takes a variable, calulates them, replaces the old value and then updates a graph, the equations seem to be working except the last, which fails to update correctly and I dont know why it won't update.

l = plot(a,b)
hold all
plot (c,d)
limx
limy

while true 
    at = a*mass/10
    at = b*mass/10
    
    %these equation equal ruffle 7.3e^-15
    a = a + at;
    b = b + bt;
    % these value would not update 
    set(1, a,b);
end

[Dyuman Joshi]

Show us the whole code, and the exact problem you are facing (values).

[Jan]

@SETH GERSBACH: "I would like if if the thread is removed so I don't get in trouble with plagerism." This is not the way a public forum works. Remember, that Google's cache store the contents of this thread already, so it cannot vanish anymore. The idea of this forum is to provide help for free and offer the solutions to all readers in the future. If you want this thread to be removed, the effort spent for helping you would be lost.

Which input arguments do you provide?

[Jan]

@SETH GERSBACH: The code fails with the message:

Undefined function or variable 'p2'.
Error in solarsystem (line 7)
R12 = norm(p2 - p1);

The readers cannot know, why the updating does not work, if the code does not run at all.

[Image Analyst]

Strange that you ask us to delete the question then you don't edit your question to remove the code, and you continue to post with the code in it. If you're going to delete the question later, don't waste people's time by continuing the discussion here.