Statistic 函数
PHP Manual

stats_dens_pmf_poisson

(PECL stats >= 1.0.0)

stats_dens_pmf_poissonProbability mass function of the Poisson distribution

说明

float stats_dens_pmf_poisson ( float $x , float $lb )

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.


Statistic 函数
PHP Manual