n=10;%number of steps
test=@(t,x) -t*x;%right-hand side of the d.e. we are using for testing purposes
t=linspace(0,4,n);%parameter
x=exp(-t.^2/2);%exact solution to our equation

[xe,t]=euler(test,1,0,4,n);%euler method
[x2,t]=rk2(test,1,0,4,n);%Runge-Kutte 2. order

figure(1);
clf
hold on
plot(t,x,'b;exact solution;');
plot(t,xe,'r;euler method;');
plot(t,x2,'g;rk2 method;');