PHP - Manual: stats_dens_pmf_poisson
2024-12-24
(PECL stats >= 1.0.0)
stats_dens_pmf_poisson — Probability mass function of the Poisson distribution
$x
, float $lb
) : float
Returns the probability mass at x
, where the random variable
follows the Poisson distribution whose parameter is lb
.
x
The value at which the probability mass is calculated
lb
The parameter of the Poisson distribution
The probability mass at x
or FALSE
for failure.
官方地址:https://www.php.net/manual/en/function.stats-dens-pmf-poisson.php