solving equations with several variables

===== Original Message From Spencer Graves <spencer.graves at pdf.com> =====
Please "reply to all".  Others on r-help may have more time than I do.
spencer graves

Josh Schmidt wrote:

I have tried optim, but I keep getting an error message.  I am quite new to
this, so perhaps I am inputting something incorrectly?

f<-function
(max,b1,precip,b2){(sum(cos(theta+2.33474-2(atan(b1*max+b2*precip)))))}

I used read.table to store the values for max, precip, and theta in those
variables.

optim(10, f, gr = NULL,

+ method = c(),
+ lower = -Inf, upper = Inf,
+ control = list(), hessian = FALSE)

Error in sum(cos(theta + 2.33474 - 2(atan(b1 * max + b2 * precip)))) :
       attempt to apply non-function
In addition: Warning message:
one-diml optimization by Nelder-Mead is unreliable: use optimize in: 

f, gr = NULL, method = c(), lower = -Inf, upper = Inf,

Josh Schmidt
Department of Biology and Wildlife
University of Alaska Fairbanks
474-7006 (office)