dt>
<dd><p>Line and marker opacity (default=0.7)</p></dd>


<dt>x2Offset</dt>
<dd><p>Vertical adjustment to secondary x-axis labels (default=5)</p></dd>


<dt>addPoints</dt>
<dd><p>Whether to add underlying data points (default=TRUE)</p></dd>


<dt>addModel</dt>
<dd><p>Whether to add the fit model with markers (default=TRUE)</p></dd>


<dt>modelSize</dt>
<dd><p>Size of model points (default=4)</p></dd>


<dt>modelColours</dt>
<dd><p>Colour of model fit markers (default="blue") as vector</p></dd>


<dt>model