b parameters</span></span>
<span><span class="va">b.init</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/rep.html" class="external-link">rep</a></span><span class="op">(</span><span class="fl">0</span>,<span class="fl">10</span><span class="op">)</span>  <span class="co"># set all item difficulties initially to zero</span></span>
<span><span class="co"># b.init &lt;- NULL</span></span>
<span><span class="va">a.init</span> <span class="op">&lt;-</span> <span class="va">Q