Hi everybody
I need to do a sum acumulative in a column of my report. I retrieve a value from the database and I fill the other columns with some mathematical operation with this value.
The last column must be the sum and in every row it must to sum the above value also: For example;

How Can i do that? I dont find the way. I had tried some variablesand things similar to : $V{var1}= $V{var1}+$V{TOC} and i get errors.!
I using Ireport 4.0.
Please let me know if that is possible in ireport?
Thanks

It will be great if you can also give us the solution

You are right sorry!

Note: my main language is not english and I dont live there, therefore i will try to write everything correctly
Here the solution:
create a variable for each operation or formula, is to say:
Variable1 = (2000/2) or (DATADB/2)
Variable2 = (2000 *60)/365 or ((DATADB*60)/365)
Variable3 = (Variable1 + Variable2)
Variable4 = (Variable3)

them in the Variable4 properties set:
Variable Class = java.lang.double
Calculation = Sum
Reset Type = Column or Page or Report (depend you case)
Increment type = Group
Increment Group = (choose the group that you created before, when you use the wizard for example you create a group)
Variable Expression = ($P{Variable3}>0) ? $P{Variable3}: 0

And ready, that is all.
Any doubt let me know
Suerte