stats_dens_pmf_negative_binomial
(PECL stats >= 1.0.0)
stats_dens_pmf_negative_binomial — Probability density function of the negative binomial distribution
说明
   stats_dens_pmf_negative_binomial
    ( float 
  $x
   , float $n
   , float $pi
   ) : float
   Returns the probability density at x, where the
   random variable follows the negative binomial distribution of which the number of the success
   is n and the success rate is pi.
  
参数
- 
x
- 
      The value at which the probability density is calculated 
- 
n
- 
      The number of the success of the distribution 
- 
pi
- 
      The success rate of the distribution 
返回值
   The probability density at x or FALSE for failure.