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

説明

float stats_dens_gamma(float $x, float $shape, float $scale)

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

パラメータ

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

戻り値

The probability density at x or false for failure.