[R-sig-ME] Formula and Start-values … nlmer (actual error messages)

[Robert Chatfield]

Hmm:  I should have included the actual error message I received from nlmer
at about the line "Could this naming be confusing to nlmer?  The start values must be named."

> first.nlmer = nlmer( y ~ a*(x+ x.nought) ~ (a|species.type) + (x.nought|id),
+      start=start.vals.1,  data=good.est.merge.long.dat  )
Error in nlmer(y ~ a * (x + x.nought) ~ (a | species.type) + (x.nought |  : 
  not all parameter names are used in the nonlinear model expression

where named list is given by ...
> start.vals.1 = c(a=aij, x.nought=C.nought.lin)
> start.vals.1[1]
         a1 
0.002266363 
> start.vals.1[3604]
x.nought1802 
  -0.1204595 

Using single values with a single name also does not work, nor does a construct
with cbind:

> first.nlmer = nlmer( y ~ a*(x+ x.nought) ~ (a|species.type) + (x.nought|id),
+      start=c(a=0.00364901,x.nought=0),  data=good.est.merge.long.dat  )
Error in nlmer(y ~ a * (x + x.nought) ~ (a | species.type) + (x.nought |  : 
  gradient attribute of evaluated model must be a numeric matrix

Bob Chatfield