This is an example of what is commonly known as "functional data
analysis,"
or "fda" for short. You can search on this term to learn more. R has
an fda package that deals with this sort of data -- and very likely
others besides: essentially you have a 200-d response vector and so
require a multivariate analysis that deals with the inherent
correlation among the wavelengths. fda seems the appropriate way to
handle this to me, but there are certainly other approaches, depending
on your context.
However, due to your relative ignorance of these matters, you would do
well to consult a local statistician to help get you started and guide
your initial forays into this arena.
-- Bert
On Tue, Oct 12, 2010 at 7:32 AM, Nevil Amos <nevil.amos at gmail.com>
wrote:> ?I have a spectrophotometric dataset with repeated measures of a value
> at 200 wavelengths for each of ?150 individuals.
>
> I would like to use the repeated samples to at each wavelength to look
> at measurement/observer error, compared to difference between
> individuals error
>
> I have looked at doing this with icc{irr} or using an anova approach,
> but I am unclear how to acheive this given that there is a nested
> structure- the value varies between wavelengths within individuals.
>
> Many thanks
>
> Nevil Amos
>
> data is structured thus:
>
>> ? ? ? ANWC_NO Wavelength Repeat ? ?value
>> 1 ? ? ? 00239 ? ? ? ?300 ? ? ? r1 0.079501
>> 2 ? ? ? 00239 ? ? ? ?302 ? ? ? r1 0.084113
>> 3 ? ? ? 00239 ? ? ? ?304 ? ? ? r1 0.087697
>> 202 ? ? 11157 ? ? ? ?300 ? ? ? r1 0.008449
>> 203 ? ? 11157 ? ? ? ?302 ? ? ? r1 0.009489
>> 204 ? ? 11157 ? ? ? ?304 ? ? ? r1 0.010142
>> 403 ? ? 11158 ? ? ? ?300 ? ? ? r1 0.026999
>> 404 ? ? 11158 ? ? ? ?302 ? ? ? r1 0.029612
>> 405 ? ? 11158 ? ? ? ?304 ? ? ? r1 0.030271
>> 604 ? ? 11159 ? ? ? ?300 ? ? ? r1 0.032784
>> 66934 ? 38711 ? ? ? ?300 ? ? ? r3 0.062081
>> 66935 ? 38711 ? ? ? ?302 ? ? ? r3 0.065137
>> 66936 ? 38711 ? ? ? ?304 ? ? ? r3 0.067092
>> 67135 ? 38712 ? ? ? ?300 ? ? ? r3 0.029389
>> 67136 ? 38712 ? ? ? ?302 ? ? ? r3 0.030192
>> 67137 ? 38712 ? ? ? ?304 ? ? ? r3 0.030860
>> 67336 ? 38993 ? ? ? ?300 ? ? ? r3 0.045720
>> 67337 ? 38993 ? ? ? ?302 ? ? ? r3 0.048060
>> 67338 ? 38993 ? ? ? ?304 ? ? ? r3 0.051898
>> 67537 ? 38994 ? ? ? ?300 ? ? ? r3 0.051815
>> 67538 ? 38994 ? ? ? ?302 ? ? ? r3 0.055162
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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>
--
Bert Gunter
Genentech Nonclinical Biostatistics