///////////////////////ATRISINAJUMA FUNKCIJA//////////////////////////

function x = funcx(x,y)
x= 0.5*x*y-0.8*y;
endfunction

function y = funcy(x,y)
y=y-0.4*x*y;
endfunction
/////////////////////Eilera Algoritms////////////////////////////////////
function [t,x,y] = euler_method_system(fx,fy,t0,x0,y0,h,b)
    n=(b-t0)/h;
    x(1)=x0;
    y(1)=y0;
    t(1)=t0;
    for i = 2:n
        t(i)= t(i-1)+h;
        x(i) =  x(i-1)+h*fx(x(i-1), y(i-1));
        y(i) = y(i-1)+h*fy(x(i-1), y(i-1));
    end
endfunction


//////////////////////////ATRISINAJUMS/////////////////////////////////
x0=3;y0=1;t0 = 0; h1=0.1;b=5;

[t1,x2,y2]=euler_method_system(funcx,funcy,t0,x0,y0,h1,b);



function dy = fun(x,y)
    dy(1)=0.5*y(1)*y(2)-0.8*y(2);
    dy(2)=y(2)-0.4*y(1)*y(2);

    //x - y(1)
    //y=y(2)
    //x'=dy(1)
    //y'=dy(2)
endfunction


yr0=[x0;y0]
yx=ode(yr0,t0,t1,fun);
plot(t1,yx(1,:),'b');
plot(t1,yx(2,:),'g');