# MATLAB: How to code two function that is separated by time

functionprogramming

Hi,
I try to code the attached equation but unable to get it work correctly. My goal is to plot those two function in one figure.
Here's my original code:
%calculate the plasma pharmacokinetics for continous injection % I used term... to simplify the long formulaDd = 50;Td = 3600;A1 = 74.6;alpha1 = 2.43*(10^(-3));A2 = 2.49;alpha2 = 2.83*(10^(-4));A3 = 0.552;alpha3 = 1.18*(10^(-5));t = 0:32400;term1 = (A1/alpha1)*(1-(exp(-alpha1*t)));term2 = (A2/alpha2)*(1-(exp(-alpha2*t)));term3 = (A3/alpha3)*(1-(exp(-alpha3*t)));term4 = (A1/alpha1).*((exp(-alpha1*t))-1).*(exp(-alpha1*t));term5 = (A2/alpha2).*((exp(-alpha2*t))-1).*(exp(-alpha2*t));term6 = (A3/alpha3).*((exp(-alpha3*t))-1).*(exp(-alpha3*t));if (t<Td)    Cv=(Dd/Td).*(term1+term2+term3);elseif (t>Td)    Cv=(Dd/Td).*(term4+term5+term6);end%calculate free doxorubicin concentration in plasma (Cfp)s = 0.25;Cfp = s*Cv;figure(1);plot (t/3600,Cfp); hold on%calculate bound doxorubicin concentration in plasma (Cfp)Cbp = (1-s)*Cv;plot (t/3600,Cbp);ylabel ('Concentration Doxorubicin in Plasma for Continuous Injection ');xlabel ('Time (hours)');legend('Cfp=free doxorubicin','Cbp=bound doxorubicin');

Cv = zeros(size(t)); %Initialise CvCv(t<Td) = (Dd/Td).*(term1(t<Td) + term2(t<Td) + term3(t<Td));Cv(t>=Td) = (Dd/Td).*(term4(t>=Td) + term5(t>=Td) + term6(t>=Td));%the logical indices are t<Td and t>=Td respectively