.org/posterior/reference/rvar.html" class="external-link">rvar</a> | <a href="https://rdrr.io/r/base/matrix.html" class="external-link">matrix</a>&gt; One of:</p><ul><li><p>A data frame (or grouped data frame as returned by <code><a href="https://dplyr.tidyverse.org/reference/group_by.html" class="external-link">dplyr::group_by()</a></code>)
that contains draws to summarize.</p></li>
<li><p>A <a href="https://mc-stan.org/posterior/reference/rvar.html" class="external-link">posterior::rvar</a> vector.</p></l