alluvium.html">geom_alluvium()</a></code>.</p>
<p>The tooltips that appear when the user hovers over elements of the plot show a text label and the number of flows included in each group. This is made relatively straightforward because if the user hovers or clicks somewhere inside a ggplot panel, Shiny automatically returns information about the location of the mouse cursor in plot coordinates. That means the main work we have to do is to extract or manually recalculate the coordinates of the different plot