function [x, y] = RK4second(t,x,y,h,g,f) k1x = h*g(t, x,y); k1y = h*f(t, x,y); k2x = h*g(t+h/3, x+k1x/3, y+k1y/3);%if it doesnt work try k1y after y k2y = h*f(t+h/3, x+k1x/3, y+k1y/3); k3x = h*g(t+2*h/3, x-k1x/3+k2x, y-k1y/3+k2y); k3y = h*f(t+2*h/3, x-k1x/3+k2x, y-k1y/3+k2y); k4x = h*g(t+h, x+k1x-k2x+k3x, y+k1y-k2y+k3y); k4y = h*f(t+h, x+k1x-k2x+k3x, y+k1y-k2y+k3y); x = x+(1/8)*(k1x+3*k2x+3*k3x+k4x); y = y+(1/8)*(k1y+3*k2y+3*k3y+k4y); end