an><span class="va">sex</span> <span class="op">~</span> <span class="va">substance</span>, data <span class="op">=</span> <span class="va">HELPrct</span>, <span class="va">table</span>, <span class="va">props</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="op">}</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   response substance female male prop_female prop_male</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1      sex   alcoho