function [t,y]=ode2(h,tspan,y0)
%differential equation solver framework using Euler method

    function y_prime=f(x,y)
        y_prime=y;
    end
tinitial=tspan(1);
tfinal=tspan(2);
tvec(1)=tinitial;
yvec(1)=y0;
for i=1:((tfinal-tinitial)/h+1)
    tvec(i+1)=tvec(i)+h;
    yvec(i+1)=yvec(i)+h*f(tvec(i),yvec(i));
    i=i+1;
end
t=tvec;
y=yvec;
end