For loop only outputting the final value.

function y = q2(t)
if 0 > t;
    y = t*sin(2*t)+sin(40+t);
elseif 0 <= t & t <= 100;
    y = t*(t-1.6*sin(25*t));
elseif 100 < t;
    y = 2*cos(t)+sin(2*t)*cos(40*t)+t;
  
    end
end

t=linspace(0,3*pi,100)
 
for t=linspace(0,3*pi,100);
    y = q2(t);
    valueOfA(t) = y;
end

Answer 1

[Cris LaPierre]

This is because you have not formatted your for loop counter correcty, and because your code replaces the value of y in each loop.

See the examples in the documentation page for capturing all the values. You might also find Ch 13 of MATLAB Onramp helpful.

Answer 2

[Rafael Hernandez-Walls]

Try using something like this:

t=linspace(0,3*pi,100)
t=linspace(0,3*pi,100);
for k=1:length(t)
    y = q2(t(k));
    valueOfA(k) = y;
end
valueOfA

Answer 3

[Walter Roberson]

Please read https://www.mathworks.com/matlabcentral/answers/395816-why-do-i-get-array-indices-must-be-positive-integers-or-logical-values-error-when-using-angle-fu#comment_882605