Contents
%%% pcount.m Photon counting examples % by Chuck DiMarzio % Northeastern University % June 2009 %
Poisson Distribution
Low mean number (0.1)
nbar=0.1;n=[0:10]; p=exp(-nbar).*nbar.^n./factorial(n); fig1=figure;bar(n,p);grid on; xlabel('n, Number'); ylabel('P(n), Probability');

Moderate mean number (1)
nbar=1;n=[0:10]; p=exp(-nbar).*nbar.^n./factorial(n); fig2=figure;bar(n,p);grid on; xlabel('n, Number'); ylabel('P(n), Probability');

Moderate mean number (3.5)
nbar=3.5;n=[0:10]; p=exp(-nbar).*nbar.^n./factorial(n); fig3=figure;bar(n,p);grid on; xlabel('n, Number'); ylabel('P(n), Probability');

Moderate mean number (50)
nbar=50;n=[20:80]; p=exp(-nbar).*nbar.^n./factorial(n); fig4=figure;bar(n,p);grid on; xlabel('n, Number'); ylabel('P(n), Probability');

Probability of 1 or more
n=0;nbar=10.^[-2:.01:1]; p0=exp(-nbar).*nbar.^n./factorial(n); % probability of zero n=1;p1=exp(-nbar).*nbar.^n./factorial(n); % probability of one fig5=figure;loglog(nbar,1-p0,nbar,1-p0-p1);grid on; xlabel('nbar, Mean number'); ylabel('P(n>0,1), Probability'); axis([1e-2,1e1,1e-4,1]); text(3e-2,1e-2,'P(n>0)'); text(3e-1,1e-2,'P(n>1)');
