Dynamic Average Line

[J Gre]

I'm trying to use to show the average production between wells on a line chart. I tried using 'Avg([Production]) over ([x])' but I get an error saying the expression is not valid. I'd like to be able to use a filter to show only some of the wells and the average line change automatically. Build version of Spotfire is 10.10.3.3 if that helps.

My data table:

 

 

 

Well

Date

Production

 

 

 

 

A

Jan 1

100

 

 

A

Jan 2

115

 

 

A

Jan 3

110

 

 

A

Jan 4

112

 

 

B

Jan 1

153

 

 

B

Jan 2

145

 

 

B

Jan 3

150

 

 

B

Jan 4

149

 

 

C

Jan 1

123

 

 

C

Jan 2

135

 

 

C

Jan 3

130

 

 

C

Jan 4

129

[Fabian Duerr]

Can you please clarify how your line chart setup looks like or send a screenshot

 

Do you want to show the average per day Or the overall average (constant value)

[J Gre]

I'd like it to show a line that is the average per day and be able to filter out a well so it would just show the average of my selection. 

 

[Fabian Duerr]

Okay, I see... The problem here is that you use the "color by" option to draw lines for each well. And this will mess up  your plot when you additionally use Avg([Production])  on the y-axis. Because this would be split as well...

 

One workaround would be to pivot your data to get a tidy dataset. Then each well has it's production data in a single column. You can do this with a transformation on your original data table. Then build a new line chart/scatterplot and put well A,B,C on the Y axis and additinolly some expression to get the average. Something like Sum([A],,[,C]) /  Count([A],,[,C])

 

But this makes filtering very hard because you would need to adjust the expression on the axis.

 

You could also work with a data function that takes your filtered original data tables as input and that returns this filtered table as a new data table. A calculated column in this table would  be dynamic in the sense that it reacts to your filtering in the source table...

 

I really can't come to a simple satisfying solution at the moment. Sorry. Let's see if other members can help.