Calculating Average dynamically in BW Report

Question

Hello experts,
I need to create a report where in I need to display month wise billing qty along with the average qty,
here 'billing qty' is a key figure and "avgqty" should be calculated dynamically.
The formula for avgqty is :
"average qty" = ("beginning qty" + "n" stock at month's end)/(n+1) where n is the monthly duration that the user gives in the selection.
ex: if the user put from "01/2006" to "03/2006" in the selection screen for the  Calendar Year/Month  then  here n becomes 2, so:
"avgqty" = (total qty for jan + total qty for feb + total qty for mar )/(2+1)
Can some please let me know the procedure on how to pass this "n" value to the formula that I need to use for my "avgqty" calculation.  
Thanks & Regds

Answer 1

Hi Murali,
i assuming You have your Month variable (MONTH)( user/entry).
First create 1 Customer Exit variable (CUMMONTH)with interval value. Go to CMOD and write this code.
DATA: L_S_RANGE TYPE RSR_S_RANGESID.
DATA: LOC_VAR_RANGE LIKE RRRANGEEXIT.
CASE I_VNAM.
WHEN 'CUMMONTH'.
IF I_STEP = 2.
"after the popup
LOOP AT I_T_VAR_RANGE INTO LOC_VAR_RANGE WHERE VNAM = 'MONTH'.
CLEAR L_S_RANGE.
L_S_RANGE-LOW = LOC_VAR_RANGE-LOW."low value = input L_S_RANGE-HIGH = LOC_VAR_RANGE-HIGH. "high value = input L_S_RANGE-SIGN = 'I'.
L_S_RANGE-OPT = 'BT'.
APPEND L_S_RANGE TO E_T_RANGE.
EXIT.
ENDLOOP.
ENDIF.
ENDCASE.
Now create a selection which have this variable CUMMONTH.( so that you get the summation of total qty from jan to qty of mar)
Now, come to your (n+1) part.
Create a formula variable (FUMMONTH)again customer exit having single value.
write this code. (not full code ..try in your system)
char l(1),
char h(1).
CASE I_VNAM.
WHEN 'FUMMONTH'.
IF I_STEP = 2.
"after the popup
LOOP AT I_T_VAR_RANGE INTO LOC_VAR_RANGE WHERE VNAM = 'MONTH'.
CLEAR L_S_RANGE.
lm = LOC_VAR_RANGE-LOW+4(2)."low value = input month
hm = LOC_VAR_RANGE-HIGH+4(2). "high value = input month
ly = LOC_VAR_RANGE-LOW(4)."low value = input year
hy = LOC_VAR_RANGE-HIGH(4). "high value = input year
'write logic
'for if user enter from 2005(ly) to 2006(hy)..
' subtract h-l and give it L_S_RANGE-LOW
L_S_RANGE-LOW = subtract
L_S_RANGE-SIGN = 'I'.
L_S_RANGE-OPT = 'EQ'.
APPEND L_S_RANGE TO E_T_RANGE.
EXIT.
ENDLOOP.
ENDIF.
ENDCASE.
after this..
Make a Formula named Avg Qty
=NODIV((That selection)(name of formula variable +1))
Hope i m clear.
Regards,
San!
Message was edited by: San!