he two groups that is created by the dichotomization (hence, <code>1-pi</code> falls into the second group). If <code>pi</code> is not specified, the function assumes <code>pi=0.5</code>, which corresponds to dichotomization at the median. The transformation is carried out as described for <code>transf.dtorbis</code>.</p></li>
<li><p><code>transf.rtorpb</code>: transformation of Pearson product-moment correlations to the corresponding point-biserial correlations, when one of the two variables is dichotomize