3.5.3.2.20 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.