R help - Nov 2004 - non-linear solve?

hi:  could someone please point me to a function that allows me to 
solve general non-linear functions?

   > irr.in <- function(r, c1, c2, c3 ) {  return(c1+c2/(1+r) + 
c3/(1+r)^2); }
  > solve.nonlinear( irr.in, -100, 60, 70 );
  0.189

If someone has written an irr function, this would be helpful, 
too---though not difficult to write, either.  thanks for any pointers.

Regards,

/iaw
---
ivo welch

See ?uniroot:
> uniroot(irr.in, c(-1, 1), c1=-100, c2=60, c3=70)
$root
[1] 0.1888196

$f.root
[1] -1.514979e-05

$iter
[1] 8

$estim.prec
[1] 6.103516e-05

Warning message: 
NA/Inf replaced by maximum positive value 

Andy
> From: ivo_welch-rstat8783 at mailblocks.com
> 
> hi:  could someone please point me to a function that allows me to 
> solve general non-linear functions?
> 
>    > irr.in <- function(r, c1, c2, c3 ) {  return(c1+c2/(1+r) + 
> c3/(1+r)^2); }
>   > solve.nonlinear( irr.in, -100, 60, 70 );
>   0.189
> 
> If someone has written an irr function, this would be helpful, 
> too---though not difficult to write, either.  thanks for any pointers.
> 
> Regards,
> 
> /iaw
> ---
> ivo welch
> 
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>

From: <ivo_welch-rstat8783 at mailblocks.com>
Date: Tue 02 Nov 2004 - 00:55:31 EST
> hi: could someone please point me to a function that allows me to
> solve general non-linear functions?
>
> > irr.in <- function(r, c1, c2, c3 ) { return(c1+c2/(1+r) +
> c3/(1+r)^2); }
> > solve.nonlinear( irr.in, -100, 60, 70 );
>   0.189
>
>   If someone has written an irr function, this would be helpful,
>   too---though not difficult to write, either. thanks for any
>   pointers.
>
>   Regards,
>
>   /iaw
optim, nlm - for general optimization;
nls, nls.lm from `minpack.lm' package - for solving the least-squares
problem.


--
WBR,
Timur