 functions more typical for <code>ggplot2</code> extensions.
The three steps of data pre-processing are:</p><table class="table table"><tr><td><strong>command</strong></td><td><strong>data processing step</strong></td></tr><tr><td><code>pcp_select</code></td><td>variable selection (and horizontal ordering)</td></tr><tr><td><code>pcp_scale</code></td><td>(vertical) scaling of values</td></tr><tr><td><code>pcp_arrange</code></td><td>dealing with tie-breaks on categorical axes</td></tr></table><p>Note that the