stats_dens_pmf_poisson
(PECL stats >= 1.0.0)
stats_dens_pmf_poisson — Probability mass function of the Poisson distribution
说明
stats_dens_pmf_poisson (
float
$x
,
float $lb
) :
float
Returns the probability mass at x
, where the random variable follows the Poisson distribution whose parameter is lb
.
参数
-
x
-
The value at which the probability mass is calculated
-
lb
-
The parameter of the Poisson distribution
返回值
The probability mass at x
or FALSE
for failure.