The screen above shows a new calculated field being added to the dictionary. A new variable named "TotalCost" is being created that will contain the sum of two database fields (INV:Quantity + INV:Cost). The evaluation process is performed at the end of the page.
The new variable was created by clicking the blue '+' button after highlighting Calculated Fields.
Calculated fields can be looked upon as temporary storage in the computers memory to perform calculations on one or more database fields. This is primarily used for (but not restricted to) calculating invoice totals, inventory balances, etc. By changing the Picture you can have the output modified to better suit your needs. For example, if you are calculating a dollar total you could use the picture @N$-10.2 to display a dollar sign in front of the calculated field.
You can also change where the evaluation process occurs. There are 4 different methods to how fields are calculated:
|•||On the start of the report|
|•||On each record|
|•||On the end of the report|
|•||On the end of the page|