x=0:1:20;

hold on
y1=poisspdf(x,1);

plot(x,y1,'Linestyle',':','Marker','o','MarkerSize',6)
axis([0 20 0 0.5])

y2=poisspdf(x,2);
plot(x,y2,'Linestyle',':','MarkerEdgeColor','green','Marker','o','MarkerSize',6)

y3=poisspdf(x,3);
plot(x,y3,'Linestyle',':','MarkerEdgeColor','red','Marker','o','MarkerSize',6)

y4=poisspdf(x,4);
plot(x,y4,'Linestyle',':','MarkerEdgeColor','black','Marker','o','MarkerSize',6)

y5=poisspdf(x,5);
plot(x,y5,'Linestyle',':','MarkerEdgeColor','cyan','Marker','o','MarkerSize',6)

legend('Poisson(1)','Poisson(2)','Poisson(3)','Poisson(4)','Poisson(5)',1);

hold off

