lumns in <code>x</code>.
When <code>TRUE</code> and <code>returnType="output"</code> the output matrix will
contain one colname for each factor level, with NA values used
to fill empty factor levels. This mechanism can be helpful to
ensure that output matrices have consistent colnames.</p></dd>


<dt id="arg-includeattributes">includeAttributes<a class="anchor" aria-label="anchor" href="#arg-includeattributes"></a></dt>
<dd><p><code>logical</code>, default FALSE, whether to include
attributes with <code>"n"