[R] Non-linear system of equations

[Gabor Grothendieck]

Try this:

> library(Ryacas)
> x <- Sym("x")
> y <- Sym("y")
> Solve(List(x^2+y^2==6, x-y==3), List(x,y))
expression(list(list(x == root(6 - y^2, 2), y == y)))


2008/4/25 Radka Pancheva <radica at abv.bg>:
> Hello R users,
>
> I am trying to estimate the parameters of a bimodal normal distribution using moments matching, so I have to solve a non-linear system of equations. How can I solve the following simple example?
>
> x^2 - y^2 = 6
> x – y = 3
>
> I heard about nlsystemfit, but I don't know how to run it exactly. I have tried the following code, but it doesn't really work:
>
>
> f1 <-y~ x[1]^2-x[2]^2-6
> f2 <-z~ x[1]-x[2]-3
> f  <- list(f1=0,f2=0)
> nlsystemfit("OLS",f,startvals=c(0,0))
>
> Thank You in advance for your help.
>
> Evgeniq Petrova
>
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