Re: computing z-scores - Mailing list pgsql-general

From Ron
Subject Re: computing z-scores
Date
Msg-id a220c1bf-ab2b-d230-7526-442716f3db5f@gmail.com
Whole thread Raw
In response to computing z-scores  (Martin Mueller <martinmueller@northwestern.edu>)
Responses Re: computing z-scores
List pgsql-general
On 05/24/2018 10:15 AM, Martin Mueller wrote:
> You construct a z-score for a set of values by subtracting the average from the value and dividing the result by the
standarddeviation. I know how to do this in a two-step procedure. First, I compute the average and standard deviation.
Ina second run I use the formula and apply it to each value.
 
>
> Is there a way of doing this in a single-step procedure or can you chain the two parts together in one query?  This
goesbeyond my SQL competence.
 

What about this?

SELECT value, (value - AVG(value))/stddev(value) as zvalue
FROM sometable
WHERE some conditions
GROUP by value


-- 
Angular momentum makes the world go 'round.


pgsql-general by date:

Previous
From: "David G. Johnston"
Date:
Subject: Re: computing z-scores
Next
From: "David G. Johnston"
Date:
Subject: Re: computing z-scores