[R-sig-ME] Convert nlme formula to nlmer

Roxane Foulser-Piggott rf371 at cam.ac.uk
Sun Jun 22 21:15:14 CEST 2014

I posted this query to the R-help list and was advised to try this mailing list:
R version 3.1.0 (2014-04-10) -- "Spring Dance”. Platform: x86_64-apple-darwin13.1.0 (64-bit).  

I would like to convert the following function from nlme to nlmer. I am finding it difficult to apply the documentation I can find on this procedure to this problem.  The function predicts earthquake ground-shaking (lnIa) as a function of M, Rrup, Ztor, Fevent, Vs30 and e1.  I am converting to nlmer, as once I have it running, I will explore crossed and nested mixed effects.

eq1 <- nlme( lnIa ~ c0 + m1*(M-5) + (r1a + r1b*M)*log(sqrt(Rrup^2 + Ztor^2)) + f1*Fevent + v1*log(Vs30/760)  + e1,fixed=c0+m1+r1a+r1b+f1+v1~1,random=e1~1|Event,data = data, start = c(c0=11,m1=-0.9,r1a=0.5,r1b=-0.52,f1=0.9,v1=-1.32))

Many thanks,

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