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

説明

float stats_dens_normal(float $x, float $ave, float $stdev)

Returns the probability density at x, where the random variable follows the normal distribution of which the mean is ave and the standard deviation is stdev.

パラメータ

x: The value at which the probability density is calculated
ave: The mean of the distribution
stdev: The standard deviation of the distribution

戻り値

The probability density at x or false for failure.