how to add calculated fields into a chart

[chongdong]

I am trying to add 2 new fields into a chart, which is calculated by the exisiting columns in the following chart. Basically I want to add A3=A2/A1, and B3=B2/B1: 

Can anyone suggest which command to use? 

[bowesmana]

Can you provide the query you are using? What happens when you tried what you tried?

[chongdong]

Just found I can directly add sum(___) and dc(___) inside chart command which solved my previous problem lol! Thanks for looking into it though. Now I have a follow up quesion about my post-analysis for adding calculated fileds into the same chart... 

[bowesmana · Accepted solution]

Try this - replace your last chart statement with these two lines - the chart just is renaming the fields and the foreach is doing the calc, i.e. Ratio=TintCount/Zones

| chart sum(tint_count) as TintCount dc(zonename) as Zones by direction type
| foreach TintCount* [ eval "Ratio<<MATCHSTR>>"='<<FIELD>>'/'Zones<<MATCHSTR>>' ]

[chongdong]

Thanks for the suggestion! But it doesn't seem to work

Is the foreach command supposed to insert a new column called Ratio in this case? 

[bowesmana]

Oops thanks @ITWhisperer pointing out the typo

[ITWhisperer]

dc(zonename) should be dc(zoneName)