Heun's method for Euler's solution

This code solves y'(t)=-2*y(t)+t with y(0)=1 using Euler method

% Initial Condition
y0 = 1;                  
h = 0.2;
% t goes from 0 to 3 seconds.
t = 0:h:3;              
% Preallocate array (good coding practice)
y_euler = zeros(size(t));  

% Initial condition gives solution at t=0.
y_euler(1) = y0;

% Solving the equation via Euler's method
for i=1:(length(t)-1)
    k1 = -2*y_euler(i)+t(i);  % Previous approx for y gives approx for derivative
    y_euler(i+1) = y_euler(i) + h*k1; % Approximate solution for next value of y
end

[Jan]

Fine. What is your question?