[R] nls error message

[Jim Bouldin]

When I try to run the following non-linear regression with  variables
index1 and prl3:

> beta = 4
> nls(index1~beta*(1/prl3),start = list(beta = 4))

I get this error message:

Error in nls(index1 ~ beta * (1/prl3), start = list(beta = 4)) : 
  REAL() can only be applied to a 'numeric', not a 'logical'

I've got no clue as to the REAL() to which this is referring.  Any help
appreciated. Thanks in advance.


Jim Bouldin
Research Ecologist
Department of Plant Sciences, UC Davis
Davis CA, 95616
530-554-1740