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Modeling polar coordinates

Titus von der Malsburg 
I'd like to fit mixed models for polar coordinates.  Each point
represents the outcome of a trial in an experiment.  Items and
subjects will be crossed random effects.  Fitting a model for the
radius component is business as usual but I don't know how to approach
the azimuth component.  The problem is that 2pi and 0 specify the same
point on a circle and that the difference between 2pi-0.1 and 0.1 is
0.2 rather than ~6.08.  Is there a way to deal with that in lme4?

R-seek didn't yield anything useful, maybe I used bad search terms.
Thanks in advance for any advice!

Best,
  Titus

Thread (6 messages)

Titus von der Malsburg Modeling polar coordinates Aug 18 Luciano Selzer Modeling polar coordinates Aug 18 Titus von der Malsburg Modeling polar coordinates Aug 18 Luca Borger Modeling polar coordinates Aug 18 Titus von der Malsburg Modeling polar coordinates Aug 24 David Duffy Modeling polar coordinates Aug 24