function FiskHai(T,n)
  
  alpha = input('alpha: ');
  beta = input('beta: ');
  epsilon = input('epsilon: ');
  gamma = input('gamma: ');
  fisk_start = input('startbestand fisk: ');
  hai_start = input('startbestand hai: ');
  
  h = T/n;
  
  x = zeros(2,1);
  x(1) = fisk_start;
  x(2) = hai_start;
  
  fisk = zeros(n+1,1);
  hai = zeros(n+1,1);
  t = zeros(n+1,1);
  fisk(1) = fisk_start;
  hai(1) = hai_start;
  
  for j=1:n   
    x = x+h*f(x,alpha,beta,epsilon,gamma);
    fisk(j+1) = x(1);
    hai(j+1) = x(2);
    t(j+1) = t(j)+h;
  end
  
  figure(2)
  plot(t,fisk,'b-','LineWidth',2)
  hold on
  plot(t,hai,'r--','LineWidth',2)
  hold off
  xlabel('Tid')
  ylabel('Bestand')
  legend('fisk','hai')
  
  min_fisk = min(fisk)
  min_hai = min(hai)
  
function y = f(x,alpha,beta,epsilon,gamma)
  
  y = zeros(2,1);
  y(1) = alpha*x(1)-beta*x(1)*x(2);
  y(2) = epsilon*beta*x(1)*x(2)-gamma*x(2);