ii) a character vector
specifying the variable(s) among Y and X that are thought to play a
role in the coarsening mechanism. To specify the outcome, use <code>"Y"</code>; to
specify covariates, use a character number corresponding to the desired
position in X (e.g., <code>"1"</code>).</p></dd>


<dt>ipc_scale</dt>
<dd><p>what scale should the inverse probability weight correction be applied on (if any)?
Defaults to "identity". (other options are "log" and "logit")</p></dd>


<dt>ipc_weights</dt>
<dd><p>weig