output argument not assigned during call

this is part of the code but i get an error that " output argument J not assigned during call" can anyone help me see where im messing up

K = linspace(-20.5,13,501);
UpperBound = 1;
LowerBound = 0;
J = MYFunction(K)

function J = MYFunction(x)

N = length(x);
for n = 1:N
    if x(n) <= -5.5
        y(n) = .2.*x(n) + 4.1;
    end
    if (x(n) > -5.5 & x(n) <= 5.5)
        y(n) = .08.*x(n).^2 + 5.42;
    end
    if x(n) > 5.5
        y(n) = -.4.*x(n) + 5.2;
    end
end

Answer 1

[Image Analyst]

Probably your y is supposed to be your J

K = linspace(-20.5,13,501);
UpperBound = 1;
LowerBound = 0;
J = MYFunction(K)

function J = MYFunction(x)
J = x; % Initialize.
y = x;
N = length(x);
for n = 1:N
    if x(n) <= -5.5
        y(n) = .2.*x(n) + 4.1;
    end
    if (x(n) > -5.5 & x(n) <= 5.5)
        y(n) = .08.*x(n).^2 + 5.42;
    end
    if x(n) > 5.5
        y(n) = -.4.*x(n) + 5.2;
    end
end
% Assign output y ==> J
J = y;

Not sure why you create UpperBound and LowerBound -- they aren't used anywhere.

[Robert Tapia]

oh the upperbound/lowerbound are used for a while loop i just didnt include it since i dont think it mattered for the error i was getting

Answer 2

[Steven Lord]

Where in your MYFunction function do you assign any value to the variable J?

[Robert Tapia]

we weren't given any values to assign to J, professor just has " define: J = MYFunction(K)" and to calculate the values for it

[Prateek Tiwari]

Hi @ Steven

Can you please help me with this,

https://nl.mathworks.com/matlabcentral/answers/557005-calling-a-function-in-matlab-function-block-in-simulink?s_tid=prof_contriblnk