MATLAB: Avoid infinity in the answer

infinity

Hi,
I am trying to run this code and, I always get infinity for my first iteration. Is there a way to avoid that? or at least filter that answers which gives infinity.
for i=1:M %for loop for M repetitions
Nx=N+randn(1,M)*CN; %excitation photon fluctuation
Nt=Nx*10.^-(E*C*l); %Nt = transmitted photons
SD2=sqrt(Nt); %This relationship is only valid for a Poisson distribution.
Nt1=Nt+randn(1,1)*SD2; %Nt = transmitted photon fluctuation
Nt2=mean(Nt1)+sqrt(Nt1)*randn(1,1); %detected photon fluctuation
A(i)=-log(Nt2/Nx); %calculation of absorbance
meanA=mean(A); %mean absorbance signal
standdeviationA=std(A); %noise
SNRUV(i)=meanA/standdeviationA %1/RSD=Signal to noise ratio for absorbance
end

Best Answer

Sorry. I had a typo in what I entered before.
The first time through the loop. what do you expect?
A is a scalar on the first time throguh. What is the standard deviationm of a scalar variable? ZERO.
Then you divide by that standard deviation, so you get inf. Only you know what it is that you SHOULD do in that case.
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