[R] nls: formula error?

[H. Paul Benton]

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,