@data is an array of references to arrays. The first array reference is the labels. Each following array reference is another curve.

What you need to do is write code to produce that kind of data structure from your incoming data, and then graph it. Before you can do that you need to specify better what your incoming data looks like. Is each file a different curve? If so then just push another anonymous array onto your building data structure. Is each file one data point on all curves? If so then be prepared to push an item onto each array reference.

Whatever the answer is, you may find references quick reference useful if you have not dealt with references before.