f 1 and a value of 0 (if the covariate is numeric).</p></dd>


<dt id="arg-t">t<a class="anchor" aria-label="anchor" href="#arg-t"></a></dt>
<dd><p>Times to calculate fitted values for. By default, these are the
sorted unique observation (including censoring) times in the data - for
left-truncated datasets these are the "stop" times.</p></dd>


<dt id="arg-start">start<a class="anchor" aria-label="anchor" href="#arg-start"></a></dt>
<dd><p>Optional left-truncation time or times.  The returned
survival, haza