(PECL stats >= 1.0.0)
stats_dens_f — Probability density function of the F distribution
Returns the probability density at x, where the
random variable follows the F distribution of which the degree of freedoms
are dfr1 and dfr2.
xThe value at which the probability density is calculated
dfr1The degree of freedom of the distribution
dfr2The degree of freedom of the distribution
The probability density at x or false for failure.