function parabolasingle(r,k,n0,nostep,maxr)
% plots a state space rendering of the May's equation

%r - intrinsic growth rate
%k - carrying capacity
%n0 - initial population size
%nostep - number of steps for simulation

%maxr is used to plot everything in the same scale if called several times

   if maxr < r
      maxr=r;
   end

   x=0:k/100:k;
   plot(x,[x;r.*x.*(k-x)./k]);
   axis([0 k 0 maxr*k/2]);
   title(r);

   hold on;
   n=maysingle(r,k,n0,nostep);
   for t=1:nostep-1
      plot([n(t) n(t)],[n(t),n(t+1)],'r')
      plot([n(t) n(t+1)],[n(t+1),n(t+1)],'r')
   end
   hold off;