 46</span>&#160;<span class="keywordflow">        end if</span></div>
<div class="line"><a name="l00047"></a><span class="lineno">   47</span>&#160; </div>
<div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;        <span class="comment">! Ensure period is a positive, non-zero value</span></div>
<div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160;        <span class="keywordflow">if</span> (period &lt; epsilon(period)) <span class="keywordflow">then</span>