Expression Error

[bhaveshp90]

Hello, 

I have a table as shown below,

I am calculating POC-Dec POC = (Current month POC)-(Last year December Month's POC)

(Sum({<Cost_Code={8}>}POC)
-
Above(TOTAL Sum({<MonthYear,Year,Cost_Code={8}>}POC), Num(Month)))

The expression is working fine, but when there is no Last year December month POC, it is showing as null value as shown in the above image;

Eg: 4.20-0= 4.20

3.80-0=3.80

How to fix this issue? attached is file for reference. 

thanks

Bhavesh

[pradosh_thakur · Accepted solution]

(Sum({<Cost_Code={8}>}POC)
-
alt(Above(TOTAL Sum({<MonthYear,Year,Cost_Code={8}>}POC), Num(Month)),0)
)

[sunny_talwar · Accepted solution]

Or use RangeSum to add two numbers where one of them can be null()

RangeSum(Sum({<Cost_Code={8}>}POC),
-Above(TOTAL Sum({<MonthYear,Year,Cost_Code={8}>}POC), Num(Month)))

[bhaveshp90]

thank you @sunny_talwar