Poisscdf

Definition:

$prob = poisscdf(k, lambda)$ computes the lower tail probabilities in given value $k$, associated with a Poisson distribution using the corresponding parameters in $\lambda$.

The lower tailed probability:
$P(X\leq k)=\sum_{i=0}^kP(X=i)=\sum_{i=0}^ke^{-\lambda }\frac{\lambda ^k}{k!}$

Parameters:

k (input,int)
The integer which defines the required probabilities. $k\geq 0$
lambda (input,double)
The parameter $\lambda$ of the Poisson distribution.$0\leq lambda\leq 1.0e6$
prob (output,double)
The probability.