function Nt=function_algae_bloom(t,N)


global mu r K

global z0 zL n D1



%Boundary conditions
N(1)=0;

N(n)=0;



%Derivative matrix
Nz=D1*N;

%second derivative matrix
Nzz=D1*Nz;



Nt=mu*Nzz+r.*N*(1-N/K);


%Boundary conditions are maintained in the derivative in respect to time
Nt(1)=0;
Nt(n)=0;