="Modified Bessel Functions of the First and Second Kinds">cyl_bessel_k</a> - refer to those
        functions for detailed accuracy information.
      </p>
<p>
        In general though, the relative error is low (less than 100 ε) for <span class="emphasis"><em>x
        &gt; 0</em></span> while only the absolute error is low for <span class="emphasis"><em>x &lt;
        0</em></span> as the following error plot illustrates:
      </p>
<div class="blockquote"><blockquote class="blockquote"><p>
          <