[R-sig-eco] segmented quantile regression and rqss

[Griffith.Michael at epamail.epa.gov]

We have been investigating quantile regression for developing stressor -
response relationships from stream monitoring data.  I would like to add
a segmented model to our analyses to look for thresholds in these
relationships.  I have figured out how to fit a model composed of
multiple linear segments using rqss.  Koenker gives an example in the
vignette for Quantile Regression in R.  However, I would like to fit a 2
- segment model.  Can anyone give me pointers on how this might be done?

Michael

Michael B. Griffith, Ph.D.
Research Ecologist

USEPA, NCEA (MS A-110)
26 W. Martin Luther King Dr.
Cincinnati, OH  45268

telephone:  513 569-7034
e-mail:  griffith.michael at epa.gov