Poisson Distribution - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English

Generates a vector of random variates from a Poisson distribution with probability \(f (X)\) defined by:

\[f(X ) = \frac{\lambda^X e^{-\lambda}}{X!}, \quad X = 0, 1, 2, \ldots\]

where λ is the mean of the distribution, LAMBDA.

C Generate 100 values from the Poisson distribution
    INTEGER LSTATE,N
    PARAMETER (LSTATE=16,N=100)
    INTEGER I,INFO,SEED(1),STATE(LSTATE)
    DOUBLE PRECISION LAMBDA
    INTEGER X(N)

C Set the seed
    SEED(1) = 1234

C Read in the distributional parameters
    READ(5,*) LAMBDA

C Initialize the STATE vector
    CALL DRANDINITIALIZE(1,1,SEED,1,STATE,LSTATE,INFO)

C Generate N variates from the Poisson distribution
    CALL DRANDPOISSON(N,LAMBDA,STATE,X,INFO)

C Print the results
    WRITE(6,*) (X(I),I=1,N)