I put an if loop inside a function and it doesn't work. It doesn't work with any loop or anything I try to add like a sub-function.

The second function in this script, d_a_const = dist_cons(v_0, v_f, t, a), doesn't work with the if loop inside it. I don't know how to fix it. It doesn't matter if I work with matrices or not, it just won't run if the loop is inside the function.

It shows this error:

Output argument "d_a_const" (and maybe others) not assigned during call to "CP_4>dist_cons".

Error in CP_4 (line 12)

d_a_const = dist_cons(v_0, t, a)

% Ejercicio 4
clc
clear

t = [1 2 1 1 3 8];
v_f = [10 10 24 24 0 0];
v_0 = [0 10 10 24 24 0];
x_0 = 0;

a = acl(v_f, v_0, t) 

d_a_const = dist_cons(v_0, t, a)

function [a] = acl(v_f, v_0, t) 

a = [(v_f - v_0) ./ t];

end
    
function d_a_const = dist_cons(v_0, t, a)

if a == 0

d_a_const = v_0 + (0.5) .* a(d_a_const) .* (t.^2);

end

end

[Stephen23]

As an aside, note that the square brackets here are superfluous and should be removed:

a = [(v_f - v_0) ./ t];
%   ^  remove these  ^

Answer 1

[the cyclist]

Because a is a vector, the if statement

if a == 0
    ...
end

will only be entered if a==0 for all elements of a. An if statement on a vector does not "loop" over the individual elements.

So, your if statement is never entered, and d_a_const is never assigned.

[Carlos Puente]

So I should do something else, or is there a solution for it?

[the cyclist]

What value do you want d_a_const to take when a is not zero?