function pemodelan_mikrobia_coli_2_umax2
clear
clc

global umax Nmax q0 N0 Ncoba tspan
umax=0.695709639;   %jam^-1
Nmax=10^7.98;      %CFU/ml
y0_awal=0; %0.005861
y0_akhir=10;
N0=10^2.85;       %CFU/ml
Ncoba=[10^2.85;10^3.5;10^3.73;10^4.01;10^4.81;10^6.21;10^7.73;10^7.79;10^7.98];

%y(1)= q
%y(2)= N

tspan=[0;2;4;6;8;12;16;20;24]; 

[solution,sse,exitflag,output]=fminbnd(@func_RMSE,y0_awal,y0_akhir)
end


function RMSE=func_RMSE(y0)
global umax Nmax q0 N0 Ncoba tspan
q=[y0;N0]  %y0=[X0 T0]
[t y]=ode23(@func_ode,tspan,q);
hasil = [t y];
Nhit=y(:,2)
Nhit2=[log10(Nhit)]'
N02=[log10(Ncoba)]'
RMSE=(sum((N02-Nhit2).^2)./length(tspan)).^0.5
%mencari R2
SStot=sum((N02-mean(N02)).^2);
SSres=sum((N02-Nhit2).^2);
R2=1-(SSres./SStot)

logNcoba=log10(Ncoba);
logNhit2=log10(Nhit);
                  % huruf dalam tanda petik kedua menyatakan betuk kurva
%plot(t,N02,'bo',t,Nhit2,'r-')     % huruf dalam tanda petik pertama menyatakan warna kurva
plot(t,logNcoba,'bo',t,logNhit2,'r-')
 end




function dy=func_ode(t,y)
global umax Nmax q0 N0

q=y(1);
N=y(2);

dq=umax.*y(1);

dN=(y(1)./(1+y(1))).*umax.*(1-(y(2)./Nmax)).*y(2);
dy=[dq;dN];
end