">pdf</span><span class="special">(</span><span class="identifier">weibull</span><span class="special">,</span> <span class="number">0</span><span class="special">)</span>
          <span class="special">==</span> <span class="number">0</span></code>).
          (Exponential and gamma distributions have similarly discontinuous functions).
        </p>
<p>
          Mathematically, the functions may make sense with an (+ or -) infinite
          value, but except for a few special cases (in the Normal and Ca