— Function: unsigned int gsl_ran_bernoulli (const gsl_rng * r, double p)

This function returns either 0 or 1, the result of a Bernoulli trial with probability p. The probability distribution for a Bernoulli trial is,

          p(0) = 1 - p
          p(1) = p

— Function: double gsl_ran_bernoulli_pdf (unsigned int k, double p)

This function computes the probability p(k) of obtaining k from a Bernoulli distribution with probability parameter p, using the formula given above.