[R] Confidence Intervals on Standard Curve

[David Winsemius]

On Feb 20, 2011, at 1:27 PM, Ben Ward wrote:

> However, the
>
> Y ~ X + Y^2
>
> Produces the best fitting line - it is pretty much on the data  
> points - I'm trying to make a standard curve, with which to take  
> readings from a spectrophotometer off of. Rather than what I would  
> normally use models for - such as hypothesis testing and analysis of  
> data from experiments.

I thought we were leaving behind the model that had the dependent  
variable on both sides of hte equation. Can you explain how you would  
construct a chart or a function that will turn those results into  
something useful?


> Thanks,
> Ben.
>
> On 20/02/2011 11:53, nzcoops wrote:
>> model<- lm(Approximate.Counts~X..Light.Transmission +
>> I(Approximate.Counts^2), data=Standards)
>>
>> Might not be addressing the problem, don't you have Y ~ X + Y^2  
>> here? That's
>> a violation of the assumptions of an lm isn't it?
>>
>> Also for plotting CI on a curve look into ggplot2::geom_ribbon,  
>> it's much
>> nicer than just plotting lines and is easy to use. had.co.nz should  
>> set you
>> right for setting this up.
>


David Winsemius, MD
West Hartford, CT