====== 감마분포와 포아송분포 관계 ======
 $X \sim G(\alpha,\beta)$이고 $Y \sim P( u/\beta )$일 때, $\alpha$가 [[정수]]인 경우

 $P( X > u ) = P(Y < \alpha )$이 성립한다.

<plot>
 set title "Gamma Distribution PDF"
 set size 1.0
 set xrange [0:20]
 set yrange [0:0.2]

 f(x,a,b) = (1/(gamma(a)*(b**a)))*(x**(a-1))*exp(-x/b)

 plot f(x,3,2.0) title "G(3,2)"
</plot>
<plot>
 set title "Poisson Distribution PMF"
 set size 1.0
 set yrange [0:0.4]
 set xrange [-0.5:8.5]

 f(x,t) = (t**(int(x)))*(exp(-t))/(int(x)!)

 plot f(x+0.5,2.5) title "P(5/2)" with steps
</plot>

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  * [[감마분포]]
  * [[포아송분포]]