[R-sig-ME] Quadratic with Random Offset in One Dimension

[ONKELINX, Thierry]

Dear Christopher,

I think this can be done with a non-linear mixed model (nlmer in lme4).

Best regards,

Thierry

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium
+ 32 2 525 02 51
+ 32 54 43 61 85
Thierry.Onkelinx at inbo.be
www.inbo.be

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~ Sir Ronald Aylmer Fisher

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-----Oorspronkelijk bericht-----
Van: r-sig-mixed-models-bounces at r-project.org [mailto:r-sig-mixed-models-bounces at r-project.org] Namens Christopher D. Long
Verzonden: zaterdag 3 maart 2012 11:42
Aan: r-sig-mixed-models at r-project.org
Onderwerp: [R-sig-ME] Quadratic with Random Offset in One Dimension

Hi,

I'm looking to fit a family of quadratics in (x,y) with a random factor offset in one variable. The model would look like this:

outcome ~ x^2 + x*(y+F) + (y+F)^2 + 1

with F a random factor.

If this were linear in x,y it'd be no problem:

outcome ~ x + y + 1|F.

Is there a way to get either lme4 to estimate a model like this?
If not, what's my best route?
--
Christopher D. Long, San Diego Padres, 100 Park Blvd, San Diego CA

"Tick, clong, tick, clong, tick, clong, went the night." - Thurber

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