The attached zip-file contains two files:
The model file opens with a Canvas where the user can input category and item names and then hit a button to create a new matrix based on the inputs.
The pdf file contains a detailed description of what is going on in the the model file and includes all the used scripts.
It is not very surprising what this model does but it may help you understanding how scripting works in Quantrix.
If you have other or simpler implementations of these functionalities just let me know.