: 0.0
</p>
<p>The accuracy of <code>romberg</code> is governed by the global variables
<code>rombergabs</code> and <code>rombergtol</code>.
<code>romberg</code> terminates successfully when
the absolute difference between successive approximations is less than <code>rombergabs</code>,
or the relative difference in successive approximations is less than <code>rombergtol</code>.
Thus when <code>rombergabs</code> is 0.0 (the default)
only the relative error test has any effect on <code>romberg</code>.
</p>
<p>