ta are circular (e.g., hours or angles). Defaults to
<code>FALSE</code> (all traits non-circular). A single logical value or a logical
vector with length equal to the number of columns in traits.</p></dd>


<dt>normal</dt>
<dd><p>if TRUE, the area under all density functions is normalized to 1,
if FALSE, the area under all density functions is proportional to the number of
observations in that group.</p></dd>


<dt>output</dt>
<dd><p>specifies whether median or mean is calculated.</p></dd>


<dt>weight_type