crosstab report how to calculate specific columns values and subtract from row total - crystal-reports

Question

am stuck at a point that in Crosstab report, i need to have sum of only two column's value and subtract the total by the value what should i do?
as in below,
Product 1 Product2 Product 3 Total
----------------------------------
Cust 1 4 5 2 11
Cust 2 5 9 7 19
I want to sum values of "Product 1","Product 3". then subtract from row total=> Total
LIKE
[4+2]-11=>TOtal.
and want to repeate this for each customer..
anyone please help me out.

Answer 1

I'm not sure when embedded summaries were introduced but I am pretty sure that your version of Crystal has this functionality. If not I apologize ahead of time. I have only been using this method for a few months now and it is quite confusing at first. At least to me but it has come in quite handy.....
I am making the following assumptions about your crosstab. Make name changes as you need to
row {yourtable.CustID}
Column {yourtable.product}
summarized field {yourtable.cost}
In the top left of your crosstab, right click go to advanced calculation and select calculated member
Select New and enter a description
For Type: Select Column
For insert Evaluation: Select After
Click edit insertion value and enter
CurrentColumnIndex=(GetNumColumns-2)//This will insert a column just before the total column
Click edit header formula and enter in quotes what you want to call the column
Select the content in Value Formulas then click Edit Value formula and number value
Save and close then exit the calculated member expert
Your crosstab should now have a new column
Right click the value go to Calculated member and select edit calculation formula
Enter this formula
(
GridValueAt (CurrentRowIndex,0 , 0) // Product 1 value
+
GridValueAt (CurrentRowIndex,2 , 0) // Product 2 value
)
-
GetTotalValueFor "yourtable.product")
NOTE: Geez it is hard to post on this site!

Answer 2

well after thinks long on it I've have done......
1st be clear that crystal report 10 is not offer following function
"CurrentRowIndex", "GridValueAt"
 
that's why above solution by "CoSpringsGuy" is not applicable.......
as we have two tables. 1 customer and 2nd for products and by both we generate crosstab with summarize field of product_sold (Qty) and 2 crosstab columns “Product.name”  and sub column product. Type
Now we want to sum value under the product.packing type =”Pilot”  of  product sold to each customer and subtract the sum-up from grand total of all products (product type “Normal” and “Pilot”)
For this problem 1st we have to work on formatting formula at crystal runtime and manipulate to “Display string” of summarize field
And then we will edit totals i.e very last column
1st edit summarize filed “display string” with the help of following code
Global CCust As String to keeping last customer for teli new customer name
Global Ccol As String ' tht is for keeping last column/product.packing type and teli with new col
Global Rndx as number ' this is for generating index of the row
Global totperx(22) as number ' is to hold the currnt value of cell and adding with previous value
' and i imagen that number of customers will less then 22 otherwise you can take unlimited array
Whileprintingrecords
if (CCust="") then
CCust=gridrowcolumnvalue("Table_Cust.Name")
Ccol=gridrowcolumnvalue("Viw_Prod.Packing")
Rndx=1
formula="new"
end if
if CCust<>gridrowcolumnvalue("Viw_Prod.Packing") then
formula="same"
Rndx=Rndx+1
else
formula="Newag"
end if
if Ccol<>gridrowcolumnvalue("Viw_Prod.Packing") then
Rndx=1
end if
if gridrowcolumnvalue("Viw_Prod.Packing")="Pilot" then
totperx(Rndx)=totperx(Rndx)+currentfieldvalue
end if
formula=totext(currentfieldvalue,0,"") ' despite of cstr function totext will change 45 to 45 while cstr changes 45 to 45.00
CCust=gridrowcolumnvalue("Table_Cust.Name")
Ccol=gridrowcolumnvalue("Viw_Prod.Packing")
now we will edit "Display String" of grand total column
Global my as number
Global totperx(22) as number
whileprintingrecords
if my<1 then
my=1
end if
formula=currentfieldvalue-totperx(my)
my=my+1