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.