The Weibull Distribution

Random: double gsl_ran_weibull (const gsl_rng * r, double a, double b)
This function returns a random variate from the Weibull distribution. The distribution function is,

p(x) dx = {b \over a^b} x^{b-1}  \exp(-(x/a)^b) dx

for x >= 0.

Function: double gsl_ran_weibull_pdf (double x, double a, double b)
This function computes the probability density p(x) at x for a Weibull distribution with scale a and exponent b, using the formula given above.