stats_harmonic_mean
(PECL stats >= 1.0.0)
stats_harmonic_mean — Returns the harmonic mean of an array of values
参数
- 
a
- 
      The input array 
返回值
   Returns the harmonic mean of the values in a,
   or FALSE if a is empty or is not an array.
  
(PECL stats >= 1.0.0)
stats_harmonic_mean — Returns the harmonic mean of an array of values
aThe input array
   Returns the harmonic mean of the values in a,
   or FALSE if a is empty or is not an array.