For those who need to display calculated fields here is a simple way to accomplish your goal.

Step 1. Add a Field to your Module to store the Computed Value
Step 2. Add the Field to your Display and List Views (Not Edit unless you want to modify metadata templates)
Step 3. Write a Insert and Update trigger in your DB to Compute the correct value.

This is much simpler than modifying the Modules php code.

This method also opens a doorway to performing more complicated Computed fields that need to reference other DB's.



Jeff