 <code>data.frame</code>
object from multiple files, like the ones provided from softwares estimating
Lagrangian models.</p>
<p>Function preprocess_graphs takes as input a list of .txt/.csv
objects. Each object represents the connections between a node and all the other
nodes. For the model to read the data, it is necessary to have all the .txt/.csv
objects in one folder. There are two ways to incorporate connectivity data,
based on their linkage to features:</p><ul><li><p>Case 1: the connectivity data corr