How do you sum the first 10 months of production for each well

[John Brand]

I have monthly production data for a bunch of wells. Each record in the monthly production data includes the 'flow month' (1,2,...,49,50, etc). How can I write an expression to sum only the first 10 months of production and then divide it by 300 for each well

[Fabian Duerr]

You can do this in two steps. My example shows this for the last two months only. Please let me know when your data structure is different:

 

First column [FirstTwoMonth]: (for two month the condition is < 3 or

[John Brand]

Thanks Fabd!  Do you know if it's possible to calculate the same thing using a custom expression in a cross table  Basically performing the calculation without having to add calculated columns to the data table

[Fabian Duerr]

Yes, this should be pretty easy. Just create your regular cross table. And then in the properties under data you can add a data limiting expression. This is always a boolean expression that evaluates to TRUE or FALSE. In my example above "[FLOWMONTH] <3" should do the job.

[John Brand]

Thanks again!