function [T,X] = euler(fun, tlims, x0, dt)
N = floor((tlims(2)-tlims(1))/dt) + 1;
T = zeros(N,1);
X = zeros(N,1);
T(1) = tlims(1);
X(1) = x0;
for n = 1:N
    T(n+1) = T(n) + dt;
    X(n+1) = X(n) + feval(fun,X(n))*dt;
end