Thanks everyone for al your help, I don't think it's necessarily as easy as
I first thought.

I'm going to have a think about it and try some things out. And I'll be
back if I get stuck!

Thanks very much,
Frances


On 4 April 2014 09:11, Keith Jewell <Keith.Jewell@campdenbri.co.uk> wrote:

> On 03/04/2014 16:26, Frances Cheesman wrote:
>
>> Hi all,
>>
>> I have a number of bacterial growth curves I would like to find the
>> equations for these and then integrate them to find the area under the
>> curves for me to do stats on later.
>>
>> Is there any way I can do this in R?
>>
>> Thanks,
>>
>> Frances
>>
>>         [[alternative HTML version deleted]]
>>
>>  Responding to the curve fitting question and passing over the
> integration issue...
>
> It is quite common to use nls to fit equations to log(count) v time data.
> You'll have to choose an appropriate model, ideally as a self starting nls
> model. Of those included in the stats package you might consider SSfpl,
> SSgompertz, SSlogis and SSweibull.
>
> But choice of a model is really a microbiological issue and all those
> models might be considered a little passe. Fitting this kind of sigmoidal
> model can be difficult unless the data is good.
>
>
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>

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