Creating calculated column in AX Reports

Let’s take a quick example of having a Unit Price and Price Unit in the PurchaseLine table. Here is how you can create a calculated column on the report to show as UnitPrice/PriceUnit.

Display method:

you can write your customized code to display/return some data on the fly of report and form execution.
Create display method in report datasource level and it will get executed for each table record.
Sample display method:-
display int Grade()
{
    emp emp;
    salgrade salgrade;
    ;
    while select grade from salgrade join  emp  where(emp.SAL>=SALGRADE.LOSAL && emp.SAL<=SALGRADE.HISAL)
    {
        return salgrade.GRADE;
    }

}

Ref: http://www.microsoftdynamicsforums.com