[R] can R solve these paired equations

Charilaos Skiadas cskiadas at gmail.com
Mon Dec 17 07:39:24 CET 2007


Turn your problem into an optimization one and use the various  
optimization abilities of R, for instance have a look at nlm:

?nlm

As an example to solve the rather simple:
x-y=0
x+y=2

We could do:

f <- function(vals) {
	x <- vals[1]
	y <- vals[2]
	sum(c(x-y,x+y-2)^2)
}
nlm(f, c(2,2))

PS: A google search for "rhelp solving nonlinear system of equations"  
would likely have given you some starting points.
PS2: Perhaps someone more expert could comment on the differences  
between optim, nlm and nlminb.

Haris Skiadas
Department of Mathematics and Computer Science
Hanover College


On Dec 17, 2007, at 12:43 AM, Xin wrote:

> Dear:
>
>
>
> I have a paired equation below. Can I solve (x,y) using R.
>
>
>
> Thanks!
>
>
>
> Xin
>
>
>
> A=327.727
>
> B=9517.336
>
> p=0.114^10
>
>
>
> (1-p)*y*(1-x)/x/(1-x^y)=A
>
> A(1+(1-x)*(1+y)/x-A))=B



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