measure to show the change in count from a set of dates

[TimIDS]

Hi

I am struggling to get a measure to show the change in count below from the import date.  There is no pattern to what the import date will be.  So for example, the measure for row 2 should show 9727-9734 = -7.  And for row 3 9743-9727 = +16

Import Date      Count

28/02/2019      9734

13/03/2019      9727

28/03/2019      9743

Can anyone help?

[parry2k]

@TimIDS is it safe to say that logic is to compare the value from previous date? if yes, what happens if there are more than two records on previous date or it will never happen?

[parry2k]

@TimIDS you can add a column like this

Diff Col = 
CALCULATE(
FIRSTNONBLANK( 'Import'[Count],1), 
FILTER( 'Import', 'Import'[Import Date] < EARLIER( 'Import'[Import Date] ) )
)

this will give you previous row value and now you can take a differnce between two columns to get the value.

[TimIDS]

 thanks but I am getting below error:

EARLIER/EARLIEST refers to an earlier row context which doesn't exist.

[parry2k]

@TimIDS are you adding it is a measure or column?

[TimIDS]

Hi,

Yes to show the change in number from previous date.  The import is only ever done once on any given day so there will never be two dates the same. Also there is a time stamp as well, even if two imports were done on same day.

thanks