Compare metric values by day

[ita_sas]

Godd morning all!

I have a VA Report in which I have lots of metrics grouped by Day, Hour and quarter of hour.

I neeed to compare the average of the values grouped by day with values of the previous day and calculate the delta.

I mean...

Let's suppose that metric average for 24/03/2015 is 10, the metric average for 25/03/2015 is 30, I need to show a row in a table in which I have:

DATE: 25/03/2015

VALUE: 30

DELTA: 20 (30 - 10)

%DELTA: 66,67% [100*(30 - 10)/30]

If I could calculate easily VALUE_FOR_YESTERDAY I'll achieve the goal!

I try to use pre-defined functions like Difference for previous period using Date, by I suppose that I can use it only to compare one day with the previous Month...

Can you help me?

[viveklanka]

If you want to calculate with the previoud row.. then it is better to use LAG funtion. or DIF

[ita_sas]

Thank you for your quick answer...

Can you explain me a little more about LAG and DIF functions?

[viveklanka]

LAG function is something which refers to the previous row.

for ex:

Name    Age

A           20

B          50

C         40

New= age-lag(age)

this gives you

Name    Age    New

A           20      .

B          50      30

C         40      10

And DIF is ,you can directly write the function DIF(age) you get the difference.

With Lag you can do any calculation with the previous row. and also with the previous row of any variable with the present row,

[ita_sas]

Thank you very much!!!

Let me try your solution

[mhamlett]

FYI

dif and lag do NOT exist in visual analytics in either the create aggregated measure or create calculated item sections.