Summarizing a formula

[qcman]

I created a formula to find the difference between one record and the previous record. My problem occurs when I want to total the formula column. I can not add a summary. If i try a formula i.e. Sum (@MBI) I get the following error message "The summary/running total could not be created

 

[synapsevampire]

Please post what's in your formula and the version of Crystal.

You might use a manual summary against it, so use the 3 formula method, you posted nothing technical so I can only guess):


Report Header Formula:
whileprintingrecords;
Numbervar MyTotalValue:=0;

Detail formula:
whileprintingrecords;
Numbervar MyTotalValue;
if {table.field} = "C"
and previous(Table.field} = "C" then
MyTotalValue:={table.value}+Previous({table.value});

Report Footer Formula:
whileprintingrecords;
Numbervar MyTotalValue

This should get you by, you might need to modify it a bit for groupings, etc.

-k

 

[qcman]

what does the "C" represent? Also what is the difference between {table.field} and {table.value}?
Also when I enter in the formula with the "C" I get an error stating a number is needed here.