[R] nls: formula error?

[Gabor Grothendieck]

The data= argument cannot be a matrix.  See ?nls

On 5/22/06, H. Paul Benton <hpbenton at scripps.edu> wrote:
> So thanks for the help,
>
> I have a matrix (AB) which in the first column has my bin numbers so -4 - +4
> in 0.1 bin units. Then I have in the second column the frequency from some
> data. I have plotted them and they look roughly Gaussian. So I want to fit
> them/ find/optimize "mu", "sigma", and "A".
>
> So I call the nls function :
>
> nls_AB <- nls(x ~ (A/sig*sqrt(2*pi))* exp(-1*((x-mu)^2/(2*
> sig^2))),data=temp, start= list(A=0.1, mu=0.01, sig=0.5), trace=TRUE)
> Error in eval(expr, envir, enclos) : numeric 'envir' arg not of length one
>
> Temp looks like this:
>       bin   x
>  [1,] -4.0   0
>  [2,] -3.9   0
>  [3,] -3.8   0
> .........etc
> [41,]  0.0 241
> [42,]  0.1 229
> [43,]  0.2 258
> [44,]  0.3 305
> [45,]  0.4 370
> [46,]  0.5 388
>
> So I don't get my error message. I looked at doing
> class(fo <- (x ~ (A/sig*sqrt(2*pi))* exp(-1*((x-mu)^2/(2* sig^2)))))
> terms(fo)
>
> and that seems to work. So if anyone has any ideas I would welcome them.
>
> Cheers,
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>