function f = economics_pde_fokker(y,t,alpha,C)

% copy of Amit's burgersa.f code to numerically evaluate the Burgers
% equation for the dimension-reduced variable.

% Initialise parameters and number of points to integrate over numerically
T = 10; L = 1000;
dt = 0.01; dx = 1.0; dy = 1.0;
f = exp(-1./(1:L));%rand(1,10000);
Lx = L/dx;
Ly = L/dy;
nt = T/dt;

% loop multiple times to improve accuracy
for j = 1:nt

% initialise derivatives
for i = 2:Lx-1
    delf(i) = (f(i+1)-f(i-1))./(2*dx);
    delsqf(i) = (f(i+1)+f(i-1)-2*f(i))/(dx*dx);
end

% initialise periodic boundary conditions
delf(1) = (f(2)-f(Ly))/2*dx;
delf(Lx) = (f(1)-f(Ly-1))/2*dx;

delsqf(1) = (f(2)+f(Ly)-2*f(1))/(dx*dx);
delsqf(Lx) = (f(1)+f(Ly-1)-2*f(Lx))/(dx*dx);

% fixed end points
f(1) = 0;
f(Lx) = 0;

% solve equation now
ftot = 0;
for k = 1:Lx
    hx = 0.01;
    f(k) = f(k) + dt*delsqf(k) + dt*(alpha+3 - C*exp(-k))*delf(k) + dt*(alpha+2)*f(k);
    ftot = ftot+f(k);
end

end

f = f./ftot;
end