Generates Poisson distributed random values.
Syntax
FORTRAN:
status = virngpoisson( method, stream, n, r, lambda )
C:
status = viRngPoisson( method, stream, n, r, lambda );
Input Parameters
Name |
Type |
Description |
|---|---|---|
method |
FORTRAN 77: INTEGER Fortran 90: INTEGER, INTENT(IN) C: const int |
Generation method. The specific values are as follows: See brief description of the PTPE and POISNORM methods in Table "Values of <method> in method parameter". |
stream |
FORTRAN 77: INTEGER*4 stream(2) Fortran 90: TYPE (VSL_STREAM_STATE), INTENT(IN) C: VSLStreamStatePtr |
Fortran: Descriptor of the stream state structure. C: Pointer to the stream state structure |
n |
FORTRAN 77: INTEGER Fortran 90: INTEGER, INTENT(IN) C: const int |
Number of random values to be generated |
lambda |
FORTRAN 77: DOUBLE PRECISION Fortran 90: REAL(KIND=8), INTENT(IN) C: const double |
Distribution parameter λ. |
Output Parameters
Name |
Type |
Description |
|---|---|---|
r |
FORTRAN 77: INTEGER*4 Fortran 90: INTEGER(KIND=4), INTENT(OUT) C: int* |
Vector of n Poisson distributed random values |
Description
The vRng"Poisson function generates Poisson distributed random numbers with distribution parameter λ, where λ∈R; λ > 0.
The probability distribution is given by:
k∈ {0, 1, 2, ...}.
The cumulative distribution function is as follows:
Return Values
- VSL_ERROR_OK, VSL_STATUS_OK
Indicates no error, execution is successful.
- VSL_ERROR_NULL_PTR
stream is a NULL pointer.
- VSL_RNG_ERROR_BAD_STREAM
stream is not a valid random stream.
- VSL_RNG_ERROR_BAD_UPDATE
Callback function for an abstract BRNG returns an invalid number of updated entries in a buffer, that is, < 0 or > nmax.
- VSL_RNG_ERROR_NO_NUMBERS
Callback function for an abstract BRNG returns 0 as the number of updated entries in a buffer.
- VSL_RNG_ERROR_QRNG_PERIOD_ELAPSED
Period of the generator has been exceeded.