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.