PHP マニュアル: Probability density function of the Weibull distribution

説明

float stats_dens_weibull(float $x, float $a, float $b)

Returns the probability density at x, where the random variable follows the Weibull distribution of which the shape parameter is a and the scale parameter is b.

パラメータ

x: The value at which the probability density is calculated
a: The shape parameter of the distribution
b: The scale parameter of the distribution

戻り値

The probability density at x or false for failure.