TestCaseMultSubs.m

% Unit tests for biofilm model
function tests = TestCaseMultSubs
clear; clc
tests = functiontests(localfunctions);
end


%% Test Diffusion
function test_mult_subs_diffusion(testCase)
% Run Test
param.mumax=2000;
param.Km=2500;
param.Yxs=[0.5 -0.278];
S=[25; 2];
param.Daq=[4e-5 6e-5];
param.De =[1e-5 1.5e-5];
Lf=5e-6;
param.LL=0;
param.Xb=20000;
param.dtol=1e-12;
param.model=[1,1];
Yps     =1.8;
param.Ns=2;
param.Nx=1;
Xbo=1;

% Growthrates for each biomass species 
param.mu{1}=@(S,param) (param.mumax*S(1))./(param.Km);

figure(1); clf(1); hold on
figure(3); clf(3); hold on

Nzs=[10,25,50,100,200]; %Grid sizes to test
error=zeros(2,length(Nzs)); %Preallocate


for i=1:length(Nzs)
    Nz=Nzs(i);
    param.Nz=Nz; 
    
    % Define Xb
    Xb=zeros(1,Nz)+param.Xb;
    
    z=linspace(0,Lf,Nz); %[m] Grid of Biofilm Depth
    dz=z(2)-z(1); %[m]
    %Sbold=linspace(0,S(1),Nz);
    Sbold=zeros(2,Nz);
    t=0;
    [Sb,~]=biofilmdiffusion_fd(Sbold,S,Xb,dz,t,param);
    figure(1);
    plot(z,Sb(1,:),'DisplayName',['Gridsize: ',num2str(Nz)])
    hold on
    
    Stest=S(2)+(param.Daq(1)*Yps/param.Daq(2))*(S(1)-Sb(1,:));
    figure(3);
    plot(z,Stest)
    hold on
    plot(z,Sb(2,:),'--')
    legend('Analytic','Numerical')
    
    
    % Analyze Result
    phi = sqrt(param.mumax*param.Xb*Lf*Lf/...
        (param.De(1)*param.Km*param.Yxs(1)));
    Sb_ana = S(1)*cosh(phi*z/Lf)/cosh(phi);
    
    % Error
    error(1,i)=mean(abs(Sb(1,:)-Sb_ana));
    error(2,i)=mean(abs(Sb(2,:)-Stest));
    

end
figure(1)
plot(z,Sb_ana,'--','DisplayName','Analytic')
xlabel('z')
ylabel('Sb(z)')
title('Substrate Profiles within Biofilm')
legend('Location','Northwest')
set(gca,'Fontsize',20)

figure(2); clf(2)
loglog(Nzs,error(1,:),'-o')
hold on
loglog(Nzs,Nzs.^-1,'--')

xlabel('Number of grid points')
ylabel('Error')
set(gca,'Fontsize',20)

figure(3)
xlabel('z')
ylabel('Sb(z)')
title('Product Profiles within Biofilm')

% Pass/fail
tol=1e-2;
verifyLessThan(testCase,min(error),tol)
end

%%