This is not a homework problem.

How to solve numerically for y from f(y,r) - a=g(y)=0? I am not too sure.

Thanks!
                       Hannah


2010/2/24 Bert Gunter <gunter.berton@gene.com>

> 1. Is this a homework problem?
>
> 2. Etiquette on this list is to sign with your full real name. Adhering to
> the list etiquette may enhance your chance of a useful response, especially
> in view of (1), as we (or at least some of us) do not wish to do students'
> homework for them.
>
> 3. Hint: f(y,r) = a  <==>  g(y) = 0 where g(y) == f(y,r) - a
> (for numerical solutions).
>
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
>  -----Original Message-----
> From: r-help-bounces@r-project.org [mailto:r-help-bounces@r-project.org]
> On
> Behalf Of li li
> Sent: Wednesday, February 24, 2010 12:46 PM
> To: r-help
> Subject: [R] Inverse function
>
> Hi all,
>   I have a function like the following:
>
>      f <- function(r,
> y){r/(2*pi)*exp(1)^(-y)*(1+r*(y/2)+r^(2)*(y-1)^(2)/6)}
>
> For fixed r, I want to find the inverse funtion in terms y.
> In other words, for fixed r, if the value of the function is given, I want
> to
> find the corrsponding y value that will achieve the specific function
> value.
>
> Can anyone help me?
>            Hannah
>
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>
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>

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