Round down a numeric
<p>I have <code>numeric</code>'s like this one:</p>

<pre><code>a &lt;- -1.542045
</code></pre>

<p>And I want to round them down (or round up the <code>abs</code>) to 2 digits after the decimal point. 
<code>signif(a,3)</code> will round it down and give me 1.54 as a result but for this example the result I want is <code>-1.55</code>.</p>

<p>Any idea?</p>