How to use nlmer on a dataset with multiple fixed and random effects

Ben Bolker · 2012-05-09T21:07:13Z

Lauren Hooton writes: > > Hello, > > I am trying to model the effect of weather variables on bat activity > (passes/hour) over three years and multiple geographic locations. > Specifically, the effects are: > > Fixed = temperature, wind speed, wind direction, pressure, > precipitation, relative humidity > Random = year, week, detector, hour > (Within each year there were multiple detectors recording bat > activity, and these detectors (locations) changed each year). >

Ben Bolker

Wed, May 9, 2012 2:07 PM

Lauren Hooton <lauren.hooton at ...> writes:

A quick question: can you use a quadratic function of one or
more of your continuous predictors in your model?  That is nonlinear
in terms of the original predictor, but it is still a linear *model*
(i.e. it is linear in terms of the parameters of the model).  You can
use either (e.g.) Pressure + I(Pressure^2), or (more numerically
stable and statistically sounder but possibly harder to interpret)
poly(Pressure,2) to add a quadratic term in Pressure ...

  (Sorry if this isn't relevant, I'm posting in a hurry)

How to use nlmer on a dataset with multiple fixed and random effects

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