Subtracting a once off value from a monthly total

[Brookied]

Hi Guys

this is driving me nuts. 

I have a a volume of income data. I have summerized this data per month on a calculated colunm

so in effect i have 

Month   ¦  Income  ¦ Tax  Ref ¦  New Colum

Jan         ¦ 125648  ¦              ¦   125648  

Feb        ¦ 125463   ¦ 256421 ¦  -130958

Mar       ¦ 586458   ¦              ¦  586458

Apr        ¦ 568412   ¦              ¦  568412

What i need to do is take away a set once off  value from Feb only -  but leave all other values the same as uneffected, then i need to do a cumulative sum on the months which i have worked out. 

This is needed to take away a tax refund in Feb that has already been allocated back to 2016 and  so should not effect 2017 income but i need to reference it.  

Any help would be great as i have gotten close but keep falling at the last hurdle

[v-caliao-msft]

@Brookied,

Not sure if I understand your requirement correctly. You can get a table like below

Month   ¦  Income  ¦ Tax  Ref ¦

Jan         ¦ 125648  ¦              ¦ 

Feb        ¦ 125463   ¦ 256421 ¦ 

Mar       ¦ 586458   ¦              ¦

Apr        ¦ 568412   ¦              ¦

And you want a calculated column in your original table

Month   ¦  Income  ¦ Tax  Ref ¦  New Colum

Jan         ¦ 125648  ¦              ¦   125648  

Feb        ¦ 125463   ¦ 256421 ¦  -130958

Mar       ¦ 586458   ¦              ¦  586458

Apr        ¦ 568412   ¦              ¦  568412

You can create a calculated column using the DAX below
New Column  =  table[Income] - table[Tax Ref]

If I have anything misunderstood, please point it out and provide us more detail information, so that we can make further analysis.

Regards,

Charlie Liao

[Brookied]

Hi Not quite mate but found a different solution, I removed the income figure from the source by using the edit query, finding the cell with the offending value and replacing with a zero.