A for loop need help ASAP

I have a loop and I want to collect the output?

A are arrays 0:300

for i = 0:3:300

Fi = atan(-(A5(1,1+i)/A5(1,2+i)));

Theta = acos(A5(1,3+i));

Psi = atan(A3(1,3+1)/A4(1,3+i));

end

[Stephen23]

Duplicate:

https://www.mathworks.com/matlabcentral/answers/459328-for-loop-collecting-output

Answer 1

[Torsten]

for i = 0:3:300
  j = i/3 + 1;
  Fi(j)= atan(-(A5(1,1+i)/A5(1,2+i)));
  Theta(j) = acos(A5(1,3+i));
  Psi(j)= atan(A3(1,3+i)/A4(1,3+i));
end

[Nikolaos Zafirakis]

Thanks for the reply, but it errors and says array indices must be positive integers or logical values!

[Torsten]

j = 0;
for i = 0:3:300
  j = j + 1;
  Fi(j)= atan(-(A5(1,1+i)/A5(1,2+i)));
  Theta(j) = acos(A5(1,3+i));
  Psi(j)= atan(A3(1,3+i)/A4(1,3+i));
end