stats_dens_exponential

(PECL stats >= 1.0.0)

stats_dens_exponentialProbability density function of the exponential distribution

说明

stats_dens_exponential ( float $x , float $scale ) : float

Returns the probability density at x, where the random variable follows the exponential distribution of which the scale is scale.

参数

x

The value at which the probability density is calculated

scale

The scale of the distribution

返回值

The probability density at x or FALSE for failure.