Here is an example of a computation which result is displayed by MaxiCharts, just as any other field. It allows user to build creative user feedbacks based on several user inputs.
In the following example, the calcuations on field Number 2 have been enabled like this:
Shortcode and graphs
[gfchartsreports gf_form_id="12" type="bar" color_set="d310" height="200px" /]