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.