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statistical advice
2 messages · Allison Brager, Greg Snow
I have had luck using the circular and the CircStats packages to look at sleep related data. I have fit mixtures of vonmeises distributions to time of occurance responses (have not looked at duration with time of occurance). There are also tools for doing regression models with circular responses (time of day) and either linear or circular predictors. If you want to use a circular predictor to predict a non-circular response then there are tools for doing periodic splines which work in that case. Hope this helps, If you give more detail of what you want to accomplish (either in the mailing list, or offline), then we/I can give more detail. -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.snow at imail.org (801) 408-8111
-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org] On Behalf Of Allison Brager
Sent: Wednesday, September 03, 2008 10:44 AM
To: r-help at r-project.org
Subject: [R] statistical advice
Hello,
I am a researcher in sleep and circadian rhythms who is
having much trouble deciding on proper statistical analyses.
Before I state my question, I provide a brief synopsis of the
looming problem; I am interested in activity bout
distributions across a 24 hr day. In addition to looking at
the number of activity bouts across the day, I am also
interested in the duration of each activity bout. My current
method of analyzing numbers and durations of activity bouts
involves; 1) documenting the number of activity bouts for
each condition (alcohol or water drinker) and then, using
repeated measures ANOVA to account for three days of activity
recording 2) displaying the number of each bout duration
(expressed in 15 minute bins) in a frequency histogram, that
again, documents differences in bout number between
conditions. My concern lies in the size of the frequency bins
for the bout durations. My advisor suggested 15 min bins, my
co-advisor suggests 60 min, I think 10 min (from
*Quantitative analysis of the age-related fragmentation of
hamster 24-h activity rhythms* by Plamen D. Penev, Phyllis C.
Zee, and Fred W. Turek) which leads me to my question: IS
THERE A MORE CONTINUOUS WAY OF ANALYZING ACTIVITY DURATION
DIFFERENCES THAT DOES NOT INVOLVE "COUNTING"?
If you would like more insight on my experiment in order to
have a more accurate understanding of the problem, please do
not hesitate to contact me.
Sincerely,
Allison Brager
--
Graduate Student
Department of Biological Sciences
Kent State University
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