precision</span> <span class="special">=</span> <span class="number">17</span><span class="special">;</span> <span class="comment">// traditional tables are only computed to much lower precision.</span>
<span class="comment">// but std::numeric_limits&lt;double&gt;::max_digits10; on new Standard Libraries gives</span>
<span class="comment">// 17, the maximum number of digits that can possibly be significant.</span>
<span class="comment">// std::numeric_limits&lt;double&gt;::digits10; == 15 is number of guar