Adding to cell above in calculated column if condition exists

[Liamnorris25]

Hi all, 

I am new to PowerBI and need some help with DAX I have already created a formula to do this in excel but am having issues in PowerBI. All suggestions are appreciated.  

Here is an image of what I am trying to do: 

I need to count all intervals that meet a condition and if they do, I want to count how many timestamps in a row this occurs for. 

So I need to access the cell in the same calculated column but on cell up. Here is the formula in excel (it is from a large spreadsheet

From 1->2 (image above)

=IF(PJ4>0,TJ3+1,0)       (PJ is from raw data, TJ is the data # 2 from the image above)

Again thank you for any help you may have!

[kentyler]

Power BI does not support referring to a previous row directly like excel does.

You can work around this.

Add an "Index" column to your data.

In your DAX measure you can use a VAR to store the value
Then use a function like CALCULATE to  access the value where the index equal your stored index - 1

VAR cur_index = SELECTEDVALUE(datatable[index])

VAR prev_index = cur_index -1

VAR myValue = CALCULATE(datatable[value],datatable[index] = prev_index)