Area Under the Curve

[c.harvey]

Hi,

I have a data set which is comprised of salivary cortisol levels taken at 5 evenly ditributed time points.

CODE; TIME1;TIME2...ETC

I want to calculate area under the curve using the trapedoizal rule for each participant and use the AUC value in my analysis,but cannot work out how to calculate AUC for each individual. Does anyone know?

Many thanks,

Chris

[Mike]

Take a look at the following:

http://www.spsstools.net/Syntax/AUC/AreaUnderTheCurveUsingTrapezoidalIntegration.txt

-Mike Palij
New York University
[hidden email]

----- Original Message -----
From: "c.harvey" <[hidden email]>
To: <[hidden email]>
Sent: Friday, January 07, 2011 11:32 AM
Subject: Area Under the Curve

> Hi,
>
> I have a data set which is comprised of salivary cortisol levels taken at 5
> evenly ditributed time points.
>
> CODE; TIME1;TIME2...ETC
>
> I want to calculate area under the curve using the trapedoizal rule for each
> participant and use the AUC value in my analysis,but cannot work out how to
> calculate AUC for each individual. Does anyone know?
>
> Many thanks,
>
> Chris
>
>
> --
> View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Area-Under-the-Curve-tp3332098p3332098.html
> Sent from the SPSSX Discussion mailing list archive at Nabble.com.
>
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[Jon K Peck]

It appears that you want the area for each record.  That would just be
compute auc = (time1 + 2*time3 + 4* (time2+time4) + time5)/width.
where width is the length of the interval between the points.

HTH,

Jon Peck
Senior Software Engineer, IBM
[hidden email]
312-651-3435



From:        "c.harvey" <[hidden email]>
To:        [hidden email]
Date:        01/07/2011 10:11 AM
Subject:        [SPSSX-L] Area Under the Curve
Sent by:        "SPSSX(r) Discussion" <[hidden email]>

---

Hi,

I have a data set which is comprised of salivary cortisol levels taken at 5
evenly ditributed time points.

CODE; TIME1;TIME2...ETC

I want to calculate area under the curve using the trapedoizal rule for each
participant and use the AUC value in my analysis,but cannot work out how to
calculate AUC for each individual. Does anyone know?

Many thanks,

Chris


--
View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Area-Under-the-Curve-tp3332098p3332098.html
Sent from the SPSSX Discussion mailing list archive at Nabble.com.

=====================
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[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD