t="_top">discrete
            distributions</a>, including the binomial, negative binomial, Poisson
            &amp; Bernoulli, are all mathematically defined as discrete functions:
            that is to say the functions <code class="computeroutput"><span class="identifier">cdf</span></code>
            and <code class="computeroutput"><span class="identifier">pdf</span></code> are only defined
            for integral values of the random variate.
          </p>
<p>
            However, because the meth