Steps taken:
1. Create a new query using the below (Administration -> Studio -> Queries)
select
@select:dim:user_def:implied:q0:id:id@,
@select:dim_prop:user_def:implied:q0:total_cost:tc@
from fin_plans
where @filter@
2. Create a portlet (Administration -> Studio -> Portlets)
3. Display the portlet in a portlet page. Adjust the layout to show both "id" and "tc" columns
4. Go to field properties of "tc" column and adjust the "Display Type" as "Bar Graph"
5. Save and Return. Export to Excel (Data Only). Note the resulting data type of "tc" column in Excel
6. Go to field properties of "tc" column and adjust the "Display Type" as "Percentage"
7. Save and Return. Export to Excel (Data Only). Note the resulting data type of "tc" column in Excel
8. Go to field properties of "tc" column and adjust the "Display Type" as "Calculated Percentage"
9. Save and Return. Export to Excel (Data Only). Note the resulting data type of "tc" column in Excel
The following results could be expected in the Excel Sheet:
--> After Step 5: A graphic is visible under "tc" column
--> After Step 7: The data type of "tc" column is "Percentage"
--> After Step 9: The data type of "tc" column is "Percentage" and the value is multiplied by 100
Actual Results:
The data type of "tc" column is always "numeric" and the exported column does not change with change in "Display Type"
This behaviour is expected since Excel inherits display directly from the attribute/field level configuration and not from Portlet Display Type.