[R] Piecewise (segmented) linear regression with center section slope constraint

[David Winsemius]

On Aug 7, 2015, at 12:05 PM, Drew Morrison wrote:

> Thanks, Jean. I've actually looked at that source before. The issue is that I
> can't constrain the slope of the /center/ section to be zero - in fact, I've
> applied similar code to a three-segment regression and I can get a zero
> slope either of the two sides, but not in the middle.

If you replaced the values during the interval in question with their mean values during that interval, you should then get a zero slope.

-- 
David.
> 
> Here's a list of the main resources I've consulted so far:
> 
> https://climateecology.wordpress.com/2012/08/19/r-for-ecologists-putting-together-a-piecewise-regression/
> 
> http://www.stackoverflow.dluat.com/questions/30060278/creating-piecewise-linear-regression-with-flat-slope-in-r
> 
> https://rpubs.com/MarkusLoew/12164
> 
> 
> 
> --
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> Sent from the R help mailing list archive at Nabble.com.
> 
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David Winsemius
Alameda, CA, USA