embedded matlab function error

in embedded matlab function file error is

Undefined function or variable 'y'. The first assignment to a local variable determines its class.

code is here:

function y  = fcn(Vreq)
%#eml

Vact=230;
duty=(Vreq/Vact);
Fs=50;
Ts=1/Fs;
i=1;
t=0:Ts:1-Ts
for k=0:Ts:1-Ts
    if(k<=duty)
        y(i)=1
    else
        y(i)=0
    end
    i=i+1;
end
end

Answer 1

[Walter Roberson]

Initialize y before the loop.

y = zeros(length(t),1);

Also you can probably change your for loop to

for k = t;

But you can replace your entire for loop with:

y = double(t <= duty);

[muhammad saad malik]

good answer, thanks, it really solved my problem