rnal-link">rowMeans</a></span><span class="op">(</span><span class="va">air</span><span class="op">$</span><span class="va">NO2</span><span class="op">)</span></span></code></pre></div>
<p>In order to perform the statistical process monitoring analysis, we
divide the data set into a phase I and a phase II dataset.</p>
<div class="sourceCode" id="cb3"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="va">rows1</span> <span class="op">&lt;-</span> <span class="fl">1</span><span 